Cisco warns customers of actively exploited zero-day in email gateways
Actively exploited Cisco Secure Email Gateway zero-day CVE-2026-76461 allows unauthenticated root command execution; CISA added it to KEV.
Cisco disclosed CVE-2026-76461, a zero-day in AsyncOS for Cisco Secure Email Gateway that was exploited before disclosure and lets unauthenticated remote attackers execute commands with root privileges on cloud and on-premises instances. CISA promptly added the flaw to its Known Exploited Vulnerabilities catalog, and Cisco has directly contacted cloud customers with indicators of compromise while deploying mitigations. Rapid7 and VulnCheck warn compromised gateways could enable silent email monitoring and internal pivoting from on-premises deployments.
Chinese espionage groups swarm to exploit triple-link chain of zero-days
At least four China-aligned espionage groups chained three zero-days in Chromium browsers and Windows ALPC for espionage since late August.
Proofpoint observed at least four state-aligned threat groups, starting with TA412/Violet Typhoon/APT31 on August 28, chaining three zero-days in the 'BlueMoon' exploit chain targeting Chrome, Chromium-based browsers and Microsoft Windows. The chain includes RCE flaws in Chromium's JavaScript engine (CVE-2026-85046, CVE-2026-87491) and a Windows Advanced Local Procedure Call privilege-escalation zero-day (CVE-2026-85880), enabling sandbox code execution, sandbox escape and system privileges. APT31 delivered the chain via phishing links to NGOs, mining and commodity trading firms in the US, installing a browser extension disguised as Google Gemini to surveil activity and steal credentials. Other groups (UNK_LateNight, UNK_DoubleCheck, UNK_QuietRacket) targeted US aerospace, Vietnamese manufacturing, and Indonesian and Singaporean organizations; fewer than 20 victims were directly observed but the true count is likely higher.
Microsoft discloses two actively exploited zero-days among 974 vulnerabilities
Microsoft patches 974 flaws in record Patch Tuesday, including two actively exploited Windows zero-days enabling privilege escalation.
Microsoft's largest-ever Patch Tuesday addresses 974 vulnerabilities, with CVE-2026-81963 (Windows Update Stack) and CVE-2026-85880 (Windows Advanced Local Procedure Call) exploited before disclosure. Both zero-days carry CVSS 7.8 ratings and allow privilege escalation. More than 10% of the defects are rated critical, and researchers attribute the record volume to AI-assisted vulnerability discovery without a matching rise in active exploitation.
Attackers exploit zero-days in consistently besieged SonicWall product
Two actively exploited SonicWall SMA 1000 zero-days chain to unauthenticated RCE; patches released and CISA added both to KEV.
SonicWall disclosed and patched two zero-days in SMA 1000 appliances: CVE-2026-83548, a maximum-severity pre-authentication SSRF, and CVE-2026-83549, a high-severity OS command injection. Rapid7 said chaining the flaws yields unauthenticated remote code execution, and CISA added both to its KEV catalog Wednesday. The vendor provided no IOCs or victim counts, urging customers to hunt for compromise, reimage or redeploy appliances, and reset all passwords and tokens. The product has faced repeated exploitation, including ransomware-linked flaws used by INC and Akira.