Cisco patches Secure Email Gateway zero-day exploited in attacks
Cisco patches actively exploited Secure Email Gateway zero-day CVE-2026-76461 enabling unauthenticated root command execution; CISA adds it to KEV.
Cisco disclosed that a critical zero-day (CVE-2026-76461) in the email parsing logic of AsyncOS for Secure Email Gateway is being actively exploited, allowing unauthenticated remote attackers to execute arbitrary SQL statements that lead to root-level command execution on virtual and physical appliances. CISA added the flaw to its KEV catalog and ordered federal agencies to patch within three days, by September 17. Cisco also patched four other critical SEG/SEWM vulnerabilities (CVE-2026-76440, CVE-2026-76441, CVE-2026-20353, CVE-2026-76443) with no evidence of exploitation, and shared IOCs including suspicious SQL statements in mail_logs.
Cisco Warns of Ongoing Exploitation of Critical Email Gateway Zero-Day
Cisco Secure Email Gateway zero-day CVE-2026-76461 (CVSS 9.8) is actively exploited for root command execution; CISA added it to KEV.
Cisco disclosed critical zero-day CVE-2026-76461 (CVSS 9.8) in Secure Email Gateway, remotely exploitable without authentication via crafted emails containing malicious SQL statements, leading to arbitrary command execution with root privileges. The flaw affects physical and virtual appliances regardless of configuration and has no workarounds. Cisco PSIRT confirmed active exploitation, and CISA added the CVE to its KEV catalog on September 14 with a federal remediation deadline of September 17. Admins should review mail_logs for suspicious SQL statements such as 'COPY.*TO PROGRAM'.
Acronis Patches Exploited Vulnerability in cPanel Backup Plugin
Acronis urgently patched CVE-2026-87886 (CVSS 7.8), insecure file permissions enabling privilege escalation, exploited in targeted attacks on cPanel & WHM backups.
Acronis released urgent patches for CVE-2026-87886 (CVSS 7.8), insecure file permissions in the Backup plugin for cPanel & WHM and the Backup extension for Plesk that allow attackers to gain elevated privileges. Exploitation has been detected in the wild in limited, targeted attacks against the cPanel & WHM plugin, but not against the Plesk extension. All Linux versions of the plugin before build 1.9.3.1021 and the Plesk extension before build 1.8.11.638 are affected; Acronis urges immediate updates and has not shared technical details.
Enterprises Warned of Attacks Exploiting WSO2 Vulnerability
Attackers are actively exploiting CVE-2026-5430 (CVSS 10), a WSO2 JWT authentication bypass, to access enterprise API credentials and sensitive data.
WatchTowr's honeypot network recorded the first exploitation attempt of CVE-2026-5430 on September 13, roughly two months after the CVE record was published in early August. The flaw, patched by WSO2 in April with an advisory in May, carries a maximum CVSS score of 10 and allows JWT authentication bypass via tokens signed with unsupported algorithms, enabling unauthorized access and full account takeover. A forged JWT observed in the wild granted access to API backend endpoints, credentials, and consumer keys and secrets for every registered application. WSO2's API Manager, API Control Plane, Traffic Manager, and Universal Gateway are affected, and the platform serves nearly 1,000 enterprise customers in banking, government, telecom, and logistics.
Adobe Commerce Zero-Day Exploited to Backdoor Online Stores
Sansec found attackers exploiting an Adobe Commerce/Magento zero-day (StyleSmuggler) since September 4 to deploy Rust backdoors on online stores.
Threat actors are actively exploiting a zero-day RCE in Adobe Commerce and Magento 2.4.7-2.4.9, injecting PHP code via generated failure reports and executing it through Magento's payment-failure email, with no user interaction required. Exploitation began September 4 and succeeds even against stores running the July and August 2026 patches; the Rust backdoor disguises itself as kworker/u:8:0 or fc-cache and hides C&C communication inside fake NTP replies. Adobe's September 8 Patch Tuesday updates may not include a StyleSmuggler fix.
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.