Sysdig has documented a real-world intrusion in which a threat actor used an LLM agent to drive post-exploitation after compromising an internet-reachable Marimo notebook via CVE-2026-39987, a pre-authentication RCE affecting all Marimo versions up to 0.20.4 (fixed in 0.23.0). The attacker extracted two cloud credentials from the host, replayed them through a fanned-out egress pool to pull an SSH private key from AWS Secrets Manager, then used it to open eight short SSH sessions against a downstream bastion. The bastion phase exfiltrated the full schema and contents of an internal PostgreSQL database in under two minutes. The May 10 incident shows attackers operationalizing AI agents for hands-on-keyboard work.
Arctic Wolf has observed active exploitation of CVE-2026-35616, an authentication-bypass flaw in FortiClient Enterprise Management Server (EMS), to deliver an undocumented credential stealer called EKZ. Attackers abuse the endpoint APIs to perform administrative actions without authentication, then modify EMS configuration and VPN policies to inject malicious scripts. Seconds after endpoints establish an IPsec tunnel to a Fortinet-managed gateway, EKZ is pushed disguised as an endpoint update via VPN scripting workflows. Fortinet released emergency hotfixes for versions 7.4.5 and 7.4.6 in early April and CISA ordered federal agencies to patch the same week; Shadowserver tracked 2,000 internet-exposed EMS instances at the time.
Microsoft has come out strongly against uncoordinated zero-day disclosures after researcher Chaotic Eclipse (also Nightmare-Eclipse) dropped technical details of six Windows zero-days over the past month, citing a breakdown in Microsoft's disclosure process. The CVEs include BlueHammer (CVE-2026-33825), RedSun (CVE-2026-41091), UnDefend (CVE-2026-45498), YellowKey (CVE-2026-45585), GreenPlasma, and MiniPlasma; BlueHammer, RedSun, and UnDefend are now under active exploitation. GitHub removed the researcher's account; a GitLab re-upload account was also blocked. Microsoft is urging coordinated vulnerability disclosure but the researcher publicly disputes Microsoft's responsiveness, citing months of waiting for fixes. The incident highlights ongoing friction between solo researchers and large vendor PSIRTs.
CISA has added three vulnerabilities to its Known Exploited Vulnerabilities catalog based on active-exploitation evidence. Two formally recognize the TeamPCP supply-chain wave that dominated mid-May: CVE-2026-45321 (TanStack) and CVE-2026-48027 (Nx Console embedded malicious code), the latter tied to the trojanized VS Code extension that led to GitHub's own 3,800-repo internal breach. The third, CVE-2026-8398, is an embedded-malicious-code flaw in the Daemon Tools Lite disc-imaging utility. FCEB agencies must remediate all three by the BOD 22-01 deadline; CISA urges all organizations to prioritize them. The additions confirm the supply-chain compromises moved from disclosure to documented in-the-wild exploitation.
Mandiant has disclosed that attackers exploited a zero-day in the KnowledgeDeliver learning management system (CVE-2026-5426) to deploy the Godzilla in-memory web shell and a custom-encrypted Cobalt Strike beacon. The flaw is a deserialization issue tied to identical pre-shared ASP.NET machine keys distributed in the vendor's default web.config across all customer deployments installed before February 24, 2026. With the shared machineKey, an attacker forges signed ViewState payloads and achieves unauthenticated RCE at the OS level. The threat actor escalated control to modify the platform's JavaScript files, prompting users to install a fake 'security authentication plugin' that delivered the Cobalt Strike payload.
CISA has given US federal civilian agencies a midnight Wednesday May 27 deadline to patch CVE-2026-9082, the highly critical Drupal SQL injection added to its Known Exploited Vulnerabilities catalog on Friday. Imperva says it has now observed 15,000+ attack attempts targeting nearly 6,000 individual Drupal sites across 65 countries since disclosure, with gaming and financial services taking almost half. Shadowserver tracks ~670 unpatched Drupal instances still exposed online (272 in North America, 273 in Europe). CISA's directive is mandatory only for FCEB agencies under BOD 22-01, but the agency strongly urges all organizations to patch immediately.
Qianxin XLab has documented a large-scale ClickFix campaign exploiting CVE-2026-26980, an SQL injection in Ghost CMS that was disclosed and patched on February 19. The vulnerability lets unauthenticated attackers read arbitrary database content including admin API keys, which are then used to inject malicious JavaScript into articles. More than 700 domains are confirmed compromised, including Harvard, Oxford, and Auburn universities and DuckDuckGo. Victim browsers receive a fingerprinted iframe overlay impersonating a Cloudflare prompt that instructs users to paste a command into the Windows command prompt, dropping DLL loaders, JS droppers, or the UtilifySetup.exe Electron-based payload. Two distinct activity clusters compete for compromised sites.
Drupal has issued an update to its highly critical PSA-2026-05-18 advisory confirming that exploit attempts for CVE-2026-9082 are now being detected in the wild. The bug is an SQL injection in Drupal's database abstraction API that lets unauthenticated requests trigger arbitrary SQL on sites running PostgreSQL, with possible escalation to RCE, privilege escalation, and information disclosure. Drupal rates it 23 out of 25 internally though NIST's CVSS v3 score is a mismatched 6.5. CISA added it to KEV on May 22. Affected versions cover Drupal 8.9.x and all 10.x and 11.x branches up to 10.4.10, 10.5.10, 10.6.9, 11.1.10, 11.2.12, and 11.3.10.
LiteSpeed Technologies has patched CVE-2026-48172, a privilege-escalation vulnerability in its cPanel plugin that lets a low-privileged cPanel user trick the plugin into running scripts as root. The flaw has been observed under active exploitation. The fix lands in cPanel plugin v2.4.7 bundled with WHM plugin 5.3.1.0. Operators who cannot patch immediately are advised to uninstall the user-end plugin via /usr/local/lsws/admin/misc/lscmctl cpanelplugin --uninstall. This follows last month's actively exploited CVE-2026-41940 (CVSS 9.8) in cPanel itself, which threat actors used to drop Mirai variants and the Sorry ransomware strain. cPanel hosting providers and resellers are the primary targets.
CISA has added two new entries to its Known Exploited Vulnerabilities catalog. CVE-2025-34291 is an origin-validation/CORS chain in Langflow, a popular open-source AI agent framework, that lets a malicious webpage exfiltrate refresh tokens and reach the code-validation endpoint for full RCE. Active exploitation began on January 23, 2026, and threat actors have been deploying the Flodric botnet through compromised instances. CVE-2026-34926 is a directory-traversal flaw in Trend Micro Apex One (On-Premise) that allows file read or write outside the intended path. FCEB agencies must remediate by June 11 per BOD 22-01; CISA urges all organisations to do the same.