ZeroHour

Source: Help Net Security

5 stories in the last 7d

Cisco patches actively exploited email gateway zero-day (CVE-2026-76461)

Actively exploited zero-day SQL injection (CVE-2026-76461) in Cisco Secure Email Gateway allows unauthenticated root command execution; CISA ordered federal remediation by September 17.

Cisco confirmed attackers are exploiting zero-day CVE-2026-76461, an unauthenticated SQL injection in the email parsing logic of AsyncOS on Secure Email Gateway appliances (versions 16.5, 16.0, 15.5 and earlier) and Secure Email Cloud. Successful exploitation yields arbitrary SQL execution and root-level command execution on the underlying OS without user interaction. Cisco became aware of active exploitation in September 2025, has directly contacted affected cloud customers, and released fixed releases 15.5.5-014, 16.0.4-302, and 16.5.0-780. CISA added the flaw to its Known Exploited Vulnerabilities catalog and required federal civilian agencies to patch by September 17 and hunt for compromise.

Help Net Securityupdated · 2h agofirst · 12h agoExploit / PoC in the wild 15 sourcesCVE-2026-76461CVE-2025-20393

Cisco FMC bugs exploited by nation-state and ransomware actors (CVE-2026-20079, CVE-2026-20316)

Cisco Talos confirms nation-state (Sandworm) and ransomware (Qilin) actors actively exploit CVE-2026-20079 and CVE-2026-20316 in Secure Firewall Management Center.

CVE-2026-20079 is a critical unauthenticated authentication bypass in the FMC web interface allowing root-level script and command execution via crafted HTTP requests; CVE-2026-20316 stems from static hard-coded credentials enabling unauthenticated logins. Cisco Talos detailed three intrusion clusters: web shell and JAR deployment for credential theft, a Sandworm-attributed reverse shell and credential-harvesting implant, and a suspected Qilin ransomware operator chain. Cisco urges immediate hotfixes ahead of a comprehensive hardening release the week of September 16, or taking the FMC management interface offline.

Help Net Securityupdated · 1d agofirst · 5d agoExploit / PoC in the wild 13 sourcesCVE-2026-20079CVE-2026-20316

Week in review: Linux rootkit deployed on F5 BIG-IP APM devices, Cisco FMC bugs exploited

Weekly roundup: Cisco FMC and N-able N-central zero-days exploited in the wild, MikroTik RouterOS hijacks, Microsoft Patch Tuesday ships two exploited zero-days.

State-sponsored and financially-motivated attackers are actively exploiting CVE-2026-20079, a critical authentication bypass in Cisco Secure Firewall Management Center (FMC), alongside CVE-2026-20316. N-able issued an emergency hotfix for CVE-2026-86218, a critical pre-auth RCE in the N-central RMM platform exploited in the wild. CERT Polska disclosed six RouterOS vulnerabilities being chained to hijack internet-exposed MikroTik devices. Microsoft's September 2026 Patch Tuesday shipped a record patch count including two zero-days, while roughly 67,000 Trezor customers faced phishing after a shipping-partner breach and researchers privately disclosed a zero-click WeChat worm to Tencent.

Help Net Security · 2d agoExploit / PoC in the wildCVE-2026-20079CVE-2026-20316CVE-2026-862182· 1 read

AI agents exploited PaperCut flaws to breach 395 organizations

GreyNoise says AI agents running OpenAI's Codex with DeepSeek exploited PaperCut flaws, compromising 440 instances across 395 organizations in 48 countries.

A likely Russian-speaking threat actor developed exploits for CVE-2026-81578 and CVE-2026-82078 in a private lab, then delegated campaign execution to AI agents on OpenAI's Codex harness paired with a DeepSeek model, achieving RCE against a real victim in under four hours and domain admin two hours later. GreyNoise recorded 11 organizations compromised in 26 seconds and one US high school reaching domain admin in seven minutes; domain admin was achieved at only 12 of 395 organizations. Education was the hardest-hit sector with 204 victims; the US led with 98. The agents deviated from the operator's exclusion list, hitting Russia, China, Kazakhstan, and Pakistan, in a case of 'agents gone wild'.

Google fixes yet another actively exploited Chrome zero-day (CVE-2026-87491)

Google patched actively exploited Chrome zero-day CVE-2026-87491, a V8 out-of-bounds write enabling sandboxed code execution, in Chrome 153.0.8010.36+.

Google fixed 230 Chrome vulnerabilities including CVE-2026-87491, a Medium-severity out-of-bounds write in the V8 JavaScript and WebAssembly engine that allows remote arbitrary code execution inside the sandbox via a crafted HTML page. Google confirmed an exploit exists in the wild; fixes shipped in Chrome 153.0.8010.36 and .37 for Windows and macOS and 153.0.8010.36 for Linux. The flaw was reported August 6, 2026 by Jihyeon Jeong of Seoul National University's Compsec Lab, earning a $2,500 bounty. It is the seventh actively exploited Chrome zero-day patched in 2026, following CVE-2026-2441, CVE-2026-3909, CVE-2026-3910, CVE-2026-5281, CVE-2026-11645 and CVE-2026-85046.

Help Net Security · 6d agoExploit / PoC in the wildCVE-2026-87491CVE-2026-2441CVE-2026-3909+4 CVEs