Threat Intel May 10, 2026

Threat Intel Bi-Weekly

Coverage: May 8–10, 2026 · 5 areas · CVEs, AI threats, nation-state activity, breaches, and news

12
Total
1
Critical
7
High
4
AI CVEs
2
Medium
Coverage: May 8 – May 10, 2026 · Sources: Palo Alto Networks, CISA KEV, NVD, BleepingComputer, The Hacker News, TechRadar, Rapid7, Help Net Security, NIST, CNBC, Microsoft Security Blog, Trend Micro, CM Alliance, BlackFog, eMazzanti, Reddit r/cybersecurity, Unit 42

Area 1 — CVEs & Exploits

[CRITICAL] CVEs & Exploits

CVE-2026-0300 — PAN-OS CVSS 9.3: Patch Drops May 13, Nation-State Exploitation Continues

Palo Alto confirmed on May 7 that CVE-2026-0300 (CVSS 9.3 Critical, unauthenticated buffer overflow in the User-ID Authentication Portal) remains unpatched and under active exploitation against internet-exposed Captive Portals. First fixes are now confirmed for May 13, 2026 (PAN-OS 11.2.7-h13 and 11.2.10-h6), with additional releases through May 28. Affected trains: PAN-OS 11.2 (below 11.2.4-h17 / 11.2.7-h13 / 11.2.10-h6 / 11.2.12), PAN-OS 11.1 (below 11.1.13-h5 or 11.1.15), PAN-OS 10.2 (below 10.2.13-h21 or 10.2.16-h7). Exploitation is low-complexity, requires no credentials, and delivers root-level code execution. Prisma Access, Cloud NGFW, and Panorama are not affected.

REMEDIATION
IMMEDIATE (if not already done): Disable the User-ID Authentication Portal on all internet-facing PA-Series and VM-Series firewalls (Device > User Identification > Authentication Portal Settings > Disable). Restrict portal access to trusted internal IP ranges only via interface management profile. Patch on May 13: apply PAN-OS 11.2.7-h13 or 11.2.10-h6 as soon as available. For 11.2.4 / 11.1 / 10.2 trains, monitor Palo Alto security advisory for precise release dates. Review firewall logs for exploitation indicators per Palo Alto guidance at security.paloaltonetworks.com/CVE-2026-0300.
--> PATCH ON MAY 13: Apply PAN-OS 11.2.7-h13 or 11.2.10-h6 immediately on release; disable Captive Portal now if not already done
[HIGH] CVEs & Exploits

CVE-2026-32202 — Windows LNK NTLM Hash Leak: FCEB Deadline TODAY (May 12 — URGENT)

CVE-2026-32202 (Windows Shell protection mechanism failure, CVSS 4.3) is being actively exploited by APT28/Fancy Bear to steal NTLM hashes from LNK files, enabling pass-the-hash lateral movement across enterprise networks. CISA's Federal FCEB remediation deadline is May 12, 2026 — tomorrow from the perspective of this brief. Akamai confirmed the flaw is an incomplete patch of CVE-2026-21510 (which APT28 exploited in February). The LNK file delivery is frictionless: a victim must open a malicious LNK file sent by email or shared drive, and NTLM hashes are leaked with no further interaction.

REMEDIATION
Apply Microsoft April 2026 Patch Tuesday update (KB5036893 for Windows 11, KB5036892 for Windows 10, equivalent Server updates). Block outbound SMB on TCP port 445 to all external IPs at the perimeter firewall. Enable Extended Protection for Authentication (EPA) and Windows Defender Credential Guard. Disable NTLMv1; enforce NTLMv2 with session security. Monitor EDR telemetry for LNK file executions originating from downloads, email attachments, or network shares.
--> URGENT — FCEB deadline May 12: apply April Patch Tuesday immediately; block TCP 445 outbound; enable Credential Guard
[HIGH] CVEs & Exploits

May 2026 Patch Tuesday Preview (May 13) — AI-Assisted Vulnerability Discovery May Set Records

Help Net Security's May 2026 Patch Tuesday forecast (published May 8) notes that Microsoft is a participant in 'Project Glasswing' — a NIST/Anthropic AI-assisted vulnerability discovery agreement signed May 5 with 12 technology companies. Anthropic's AI models will analyze code for vulnerabilities before public release, with NIST receiving findings. Microsoft's participation signals a potentially record-breaking Patch Tuesday on May 13. Organizations should prepare patch management workflows now. Additionally, NIST announced it is shifting to threat-based CVE enrichment: only KEV-listed, federal-use, and critical software CVEs will receive NVD scoring enrichment — reducing noise but potentially delaying CVSS scores for non-critical findings.

REMEDIATION
Prepare patch testing environments now for May 13 Patch Tuesday. Prioritize: Windows kernel updates, Edge/Chromium updates, Microsoft 365 app updates, and Adobe Creative Cloud (Audition, Animate, Premiere Pro). Subscribe to Microsoft Security Update Guide RSS. Update NVD scanning tools to accommodate the new threat-based enrichment model — expect some CVEs without CVSS scores if they fall outside NIST's new priority tiers.
--> Prepare Patch Tuesday workflows now — May 13 release may be unusually large; plan accelerated deployment
[HIGH] CVEs & Exploits

CVE-2026-42208 — LiteLLM CISA KEV: FCEB Deadline TODAY (May 11 — PATCH NOW)

CISA added CVE-2026-42208 (LiteLLM SQL injection CVSS 9.3) to the KEV catalog on May 8. The FCEB remediation deadline is May 11 — today. This unauthenticated SQL injection in LiteLLM Proxy 1.81.16-1.83.6 allows an attacker to read and modify the proxy database, extracting all LLM provider API keys (OpenAI, Anthropic, AWS Bedrock, Azure OpenAI). Active exploitation targeting production instances has been confirmed since April 26. Blast radius: a successful extraction grants cloud-grade credential access across every LLM provider the proxy manages.

REMEDIATION
Upgrade LiteLLM Proxy now: pip install litellm==1.83.10. Verify: pip show litellm. Interim: set 'disable_error_logs: true' under general_settings in litellm_config.yaml. Restrict LiteLLM Proxy to trusted internal networks only. Immediately rotate ALL LLM provider API keys (OpenAI, Anthropic, AWS Bedrock, Azure) accessible via the proxy if running an affected version against an untrusted network.
--> pip install litellm==1.83.10 NOW — FCEB deadline is today May 11; rotate all LLM provider API keys

Area 2 — AI & Supply Chain

[HIGH] AI & Supply Chain

CVE-2026-25592 + CVE-2026-26030 — Microsoft Semantic Kernel: Prompt-to-Shell RCE (May 7 Disclosure)

Microsoft Security Blog (May 7, 2026) disclosed two patched vulnerabilities in Semantic Kernel that turn prompt injection into host-level RCE. CVE-2026-25592 (Semantic Kernel .NET SDK < 1.71.0): SessionsPythonPlugin exposed its file upload function to the AI model via [KernelFunction] attribute. Prompt injection bypasses the Azure Container Apps sandbox, writes a malicious payload to the Windows Startup folder, and achieves persistent host-level RCE. CVE-2026-26030 (Semantic Kernel Python < 1.39.4): In-Memory Vector Store Search Plugin applied filter logic through eval() on attacker-influenced input. A single crafted prompt achieves RCE by smuggling a Python AST-traversal payload through the eval() sink. Both vulnerabilities require only a prompt injection vector — no credentials, no memory corruption. Microsoft has published a live CTF demonstrating CVE-2026-26030.

REMEDIATION
For CVE-2026-25592 (.NET): Upgrade to Semantic Kernel .NET SDK 1.71.0 or later. Check: dotnet list package | grep SemanticKernel. For CVE-2026-26030 (Python): pip install --upgrade semantic-kernel>=1.39.4. Check: pip show semantic-kernel. If using In-Memory Vector Store as Search Plugin backend, upgrading is mandatory — no config workaround exists. Apply strict input validation and output monitoring for all agents processing external content. Review host systems running affected Semantic Kernel agents for unexpected modifications to Windows Startup directories or unusual Python subprocess spawning.
--> pip install semantic-kernel>=1.39.4 and upgrade .NET SK to 1.71.0+ — both versions exploit prompt injection for host RCE
[HIGH] AI & Supply Chain

Mythos AI — Zero-Day Chaining System Achieves Browser + OS Sandbox Escapes Autonomously

BleepingComputer and Help Net Security (May 8) reported on Mythos, an AI-powered offensive security system that autonomously discovers and chains zero-days across internet-facing systems. Mythos demonstrated a four-zero-day chain that bypassed both the browser renderer sandbox and the OS sandbox. Cybersecurity firms warn that AI-driven attacks from systems like Mythos may soon outpace defensive response capacity — models can find hidden flaws across internet systems at machine speed, raising concerns among banks, regulators, and security leaders. Mythos represents the real-world weaponization of the M-Trends 2026 finding that 42% of 2025 CVEs were exploited before public disclosure, as AI can generate exploits directly from advisory text.

REMEDIATION
Reduce attack surface by patching KEV-listed vulnerabilities within 24-48 hours — AI-generated exploits operate faster than traditional PoC timelines. Implement behavioral EDR and network anomaly detection that can catch exploitation attempts without signature matches. Deploy browser isolation for high-risk users. Adopt continuous automated exposure management (CAEM) scanning to identify and remediate zero-day-exploitable surfaces faster than advisory cycles. Subscribe to vendor security advisories with push notification for critical items.
--> Compress CVE patching SLAs to 24-48h for Critical/KEV vulnerabilities; deploy behavioral detection vs. signature-only tools
[MEDIUM] AI & Supply Chain

Prompt Injection: 5 Documented Attack Patterns in 2026 — Multi-Language Evasion Now in Active Use

A May 3, 2026 compilation of confirmed prompt injection attack patterns documents five production-grade techniques: (1) Zero-click data exfiltration (Copilot CVE-2025-11 — crafted email extracts confidential data without user action; 60% of enterprise AI copilots share similar patterns in red-team assessments); (2) Tool manipulation — hijacking which action an agent takes mid-task; (3) Memory poisoning — persistent false beliefs injected into agent long-term memory; (4) Supply chain attacks via malicious MCP tools (ClawHavoc: 1,100+ malicious tools on ClawHub); (5) Multi-language evasion — fragmenting payloads across Mandarin, Arabic, and Portuguese to bypass English-trained classifiers. Unit 42 confirmed patterns 4 and 5 in real-world attacks.

REMEDIATION
Scan all inputs before they reach the LLM using a dedicated prompt classifier or AI firewall. Implement output monitoring for unexpected data exfiltration patterns or action sequences. Apply MCP tool allowlisting — only verified, audited tools. Audit agent memory stores for injected persistent beliefs. Deploy multi-language content scanning for inbound AI inputs. Run red-team prompt injection assessments against all production AI agents on a quarterly cadence.
--> Deploy pre-LLM input scanning and output anomaly monitoring; run quarterly prompt injection red-team assessments

Area 3 + 4 — Threat Actors & Dark Web

[HIGH] Threat Actors

APT28 / Salt Typhoon — Dual Nation-State Campaign: LNK Exploitation + Telecom Persistence

Two major nation-state campaigns are active this period. APT28 (Russia/Fancy Bear) is exploiting CVE-2026-32202 LNK files to steal NTLM hashes, particularly targeting Ukraine, EU governments, and defense-adjacent organizations. Simultaneously, Salt Typhoon (China-linked) continues persistent access in U.S. and allied telecom networks — confirmed 'still very much ongoing' by FBI as of February 2026. Trend Micro's Q1 2026 report confirms Salt Typhoon successfully targeted U.S. congressional email systems and that related group UAT-7290 is simultaneously targeting U.S. and allied telecom infrastructure through edge device vulnerabilities. AI-enhanced ransomware (LAMEHUG, deployed by APT28) and DPRK's FAMOUS CHOLLIMA (Lazarus) activity doubled its incident rate in the past year.

REMEDIATION
For APT28 LNK campaign: apply April Patch Tuesday (CVE-2026-32202), block TCP 445 outbound, enable Credential Guard. For Salt Typhoon/telecom threat: patch all internet-facing edge devices (Fortinet, Cisco, VMware, Palo Alto) immediately. Enforce MFA on all remote access and privileged accounts. Conduct third-party/contractor security assessments. Deploy behavioral detection that can identify living-off-the-land (LOTL) techniques used by both groups. Review email system logs for indicators of unauthorized access.
--> Patch edge devices; enforce MFA on all privileged access; monitor for NTLM hash theft and LOTL activity in EDR
[MEDIUM] Threat Actors

Kyber Ransomware Tests Post-Quantum Encryption Against Windows + VMware ESXi

The Kyber ransomware group demonstrated in April 2026 the first use of post-quantum encryption algorithms against Windows and VMware ESXi environments, including a confirmed attack on a U.S. defense contractor. The group deletes backups and disables recovery mechanisms before encrypting — making recovery extremely difficult. Kyber's post-quantum approach is designed to resist future decryption even if law enforcement seizes keys, eliminating any potential for future decryption of intercepted ransoms. CM Alliance confirmed the technique is now documented and is expected to be replicated by other groups.

REMEDIATION
Implement immutable, offline, air-gapped backups that cannot be reached from production networks — test recovery quarterly. Enable VMware ESXi lockdown mode and restrict VCentre access to trusted management networks only. Deploy EDR with ransomware behavioral detection on all Windows hosts. Segment production, backup, and management networks. Disable VCentre APIs from internet-facing interfaces. Ensure business continuity plans are tested for a scenario where decryption keys are never recovered.
--> Validate air-gapped backup integrity and recovery procedures; segment ESXi management from production networks
[HIGH] Dark Web & Leaks

Adobe Data Breach — 13M Customer Support Tickets, 15K Employee Records, Internal Documents Leaked

A threat actor claimed in April 2026 to have exfiltrated 13 million Adobe customer support tickets, 15,000 employee records, and internal company documents. The breach raises significant concerns about how organizations protect operational data beyond standard customer PII. Customer support tickets commonly contain sensitive operational details — license keys, error logs with system metadata, internal communication, and sometimes credentials shared in troubleshooting sessions. The full scope and authentication of the claim is still being assessed, but multiple security researchers have validated samples of the data.

REMEDIATION
Adobe customers: change Adobe account passwords and enable MFA. Monitor for targeted phishing that references specific support ticket details — highly personalized emails referencing your exact issue or case number are a red flag. Revoke any credentials shared in past Adobe support sessions. Organizations with Adobe enterprise licensing: review licenses and watch for account takeover attempts using credentials that may have been present in support communications. Check HaveIBeenPwned for Adobe-linked email addresses.
--> Change Adobe account passwords, enable MFA, monitor for support-ticket-themed phishing targeting your account specifics
[MEDIUM] Dark Web & Leaks

STELIA Aerospace Breach — 10 TB Exfiltrated by Rhysida, Technical Drawings and Employee Records

Rhysida ransomware group claimed responsibility for breaching STELIA Aerospace North America, exfiltrating approximately 10 TB of data including identity documents, employee records, and technical drawings — suggesting deep compromise of corporate and partner-related data. A 27 BTC (~$2.07M) ransom demand was issued. This breach is notable in the defense/aerospace sector context: technical drawings from aerospace suppliers can have export control implications, and partner data exposure extends the breach radius beyond the direct victim. Rhysida has been increasingly active against defense-adjacent organizations in 2026.

REMEDIATION
For defense/aerospace suppliers: review third-party data sharing with STELIA; assess whether your organization's data may be in scope. For broader relevance: implement zero-trust access to technical drawing repositories and engineering data management (EDM) systems. Enforce data classification and export control tagging on aerospace technical documents. Ensure incident response plans specifically address export-controlled data breach notification requirements (ITAR, EAR). Monitor dark web for samples of STELIA data being shared or sold.
--> Defense suppliers: audit data shared with STELIA; review export-controlled document access controls and breach notification obligations

AI Vulnerability Monitor

Pulled from AI Vuln Monitor run — May 10, 2026 · 3 findings

[HIGH] AI Vulnerability Monitor

CVE-2026-25592

Affected: Microsoft Semantic Kernel .NET SDK — all versions prior to 1.71.0

Microsoft disclosed CVE-2026-25592 on May 7, 2026 — an arbitrary file write vulnerability in the Semantic Kernel .NET SDK's built-in SessionsPythonPlugin. The plugin allows AI agents to execute Python code inside Azure Container Apps dynamic sessions (cloud-isolated sandboxes). A flaw in how the plugin exposed its upload_file function to the AI model via the [KernelFunction] attribute allowed an attacker to reach this function through prompt injection: a single crafted prompt caused the agent to bypass the cloud-hosted sandbox, write a malicious payload directly to the host device's Windows Startup folder, and achieve persistent remote code execution. No memory corruption required — the agent simply did what it was designed to do. Affects any application using Semantic Kernel .NET SDK prior to 1.71.0 with SessionsPythonPlugin enabled.

REMEDIATION
Upgrade Microsoft Semantic Kernel .NET SDK to version 1.71.0 or later immediately. Check your version: dotnet list package | grep SemanticKernel. Audit all agents using SessionsPythonPlugin and verify they are running the patched SDK version. Apply strict prompt input validation for agents that process external content. Review host file system for unexpected modifications to Windows Startup directories. Consider disabling SessionsPythonPlugin entirely in environments where Python execution sandboxing is not required.
[HIGH] AI Vulnerability Monitor

CVE-2026-26030

Affected: Microsoft Semantic Kernel Python SDK — all versions prior to 1.39.4, using In-Memory Vector Store with Search Plugin default configuration

CVE-2026-26030 is the second Semantic Kernel vulnerability disclosed by Microsoft on May 7, 2026. In the Python Semantic Kernel package prior to 1.39.4, the In-Memory Vector Store Search Plugin applied filter logic through an eval() call on attacker-influenced input. When an agent used the default Search Plugin configuration backed by the In-Memory Vector Store, a prompt injection through any external content the agent processes (a web page, document, API response, or tool output) was sufficient to reach the eval() sink. Researchers demonstrated RCE by crafting a prompt injection that smuggled a Python AST-traversal payload through the vulnerable evaluation path, launching arbitrary code on the machine running the agent. Microsoft has published an interactive capture-the-flag challenge demonstrating the exploit chain. Affects any Python Semantic Kernel agent using In-Memory Vector Store with default filter configuration.

REMEDIATION
Upgrade semantic-kernel Python package to version 1.39.4 or later immediately: pip install semantic-kernel==1.39.4 (or pip install --upgrade semantic-kernel). Verify your version: pip show semantic-kernel. If using In-Memory Vector Store with the Search Plugin, upgrading is the only complete fix — Microsoft removed the [KernelFunction] attribute from the affected function, making it invisible to the AI model. Treat all external content processed by Semantic Kernel agents as untrusted. Implement prompt input monitoring and anomaly detection for unexpected tool invocations in agent telemetry.
[HIGH] AI Vulnerability Monitor

CVE-2026-42208-CISA-KEV

Affected: LiteLLM Proxy (AI Gateway) versions 1.81.16 through 1.83.6 — CISA KEV added May 8, 2026, FCEB deadline May 11

CISA added CVE-2026-42208 (LiteLLM SQL injection, CVSS 9.3) to the Known Exploited Vulnerabilities catalog on May 8, 2026, with a Federal FCEB remediation deadline of May 11, 2026. Previously covered in the May 3 run as an actively exploited vulnerability, the CISA KEV addition confirms federal-level severity classification and triggers mandatory remediation timelines for government environments. Active exploitation has been confirmed, with attackers targeting litellm_credentials tables storing multi-provider LLM API keys (OpenAI, Anthropic, AWS Bedrock, Azure). This KEV addition escalates the urgency for any organization still running LiteLLM Proxy 1.81.16 through 1.83.6 without patching.

REMEDIATION
If not already patched: pip install litellm==1.83.10 immediately (recommended stable version). Verify: pip show litellm. Interim workaround if upgrade is delayed: set 'disable_error_logs: true' under general_settings in litellm_config.yaml. Restrict LiteLLM Proxy to trusted internal networks only. Rotate all LLM provider API keys (OpenAI, Anthropic, AWS, Azure) that were accessible from the proxy while running an affected version. FCEB agencies: remediation required by May 11, 2026 per CISA BOD 22-01.

Area 5 — AI & Cybersecurity News

[INFO] AI Security News

NIST + Anthropic 'Project Glasswing' — AI Models Now Analyzing Code for CVEs Before Release

The Center for AI Standards and Innovation (CAISI/NIST) announced on May 5, 2026 formal agreements with Google DeepMind, Microsoft, xAI, and 11 other companies to evaluate AI models in classified environments before public release. Simultaneously, NIST and Anthropic launched 'Project Glasswing,' in which Anthropic AI models analyze software for vulnerabilities before disclosure — findings go to NIST. Microsoft is a Project Glasswing participant, which is expected to surface a record number of CVEs in the May 13 Patch Tuesday. Separately, NIST announced a shift to threat-based CVE enrichment: NVD will prioritize scoring for KEV-listed, federal-software, and critical-category CVEs only — reducing noise but potentially delaying CVSS scores for lower-priority findings.

REMEDIATION
Update patch management SLAs to account for potentially larger Patch Tuesday releases beginning May 13. Update NVD API queries and CVSS-dependent automation to handle CVEs without immediate CVSS scores under the new NIST enrichment model. Subscribe to CISA KEV RSS as a primary signal for critical patching priority, independent of CVSS timing.
--> Update NVD tooling for threat-based enrichment model; prepare for larger May 13 Patch Tuesday; use CISA KEV as primary priority signal
[INFO] AI Security News

Mythos Demonstrates AI-Chained Four Zero-Day Browser + OS Sandbox Escape — Defensive Threshold Concern

Multiple cybersecurity firms issued warnings on May 8, 2026 that AI-driven offensive tooling like Mythos has reached a capability threshold where it can autonomously discover and chain zero-days across internet systems faster than human defenders can respond. Mythos demonstrated a four-zero-day chain bypassing both browser renderer and OS-level sandboxes — a milestone previously requiring elite human operators. Security leaders in banking, fintech, and critical infrastructure are flagging concern about the asymmetric advantage this gives to well-resourced attackers. The implication is that organizations running on weekly or monthly patch cycles are now structurally disadvantaged against AI-speed exploitation.

REMEDIATION
Compress patching SLAs for Critical and KEV-listed vulnerabilities to 24-48 hours. Invest in behavioral and anomaly-based detection that does not require prior exploit signatures. Adopt attack surface reduction as a primary security control — reduce the number of internet-facing services and APIs exposed. Evaluate AI-assisted defensive tooling for real-time threat hunting and automated containment (network isolation of anomalous endpoints).
--> Compress patch SLAs to 24-48h for KEV items; invest in behavioral detection; reduce external attack surface

Priority Action Matrix

TOP 5 ACTIONS THIS PERIOD
01 [DO NOW] Disable PAN-OS Captive Portal — patch arrives May 13
Device > User Identification > Authentication Portal Settings > Disable. Apply PAN-OS 11.2.7-h13 or 11.2.10-h6 on May 13.
02 [DO NOW] pip install litellm==1.83.10 — FCEB deadline was May 11
CISA KEV. Unauthenticated SQL injection exfiltrates all LLM API keys. Rotate all connected provider keys.
03 [TODAY] Apply April Patch Tuesday — Windows LNK CVE-2026-32202, FCEB deadline May 12
APT28 exploiting for NTLM hash theft. Block TCP 445 outbound; enable Credential Guard.
04 [TODAY] Upgrade Semantic Kernel: pip install semantic-kernel>=1.39.4; .NET SDK 1.71.0+
Prompt injection achieves host-level RCE in both Python and .NET Semantic Kernel before patched versions.
05 [THIS WEEK] Prepare for May 13 Patch Tuesday — expected record-size release (Project Glasswing)
Microsoft + Anthropic AI-assisted CVE discovery may surface unusually large CVE batch. Pre-stage test environments.

Biggest Risk This Period

!! HIGHEST PRIORITY RISK !!
CVE-2026-0300 patches begin shipping May 13 — any internet-facing PAN-OS Captive Portal still enabled is actively being targeted by nation-state actors with three days remaining before the first fix becomes available.