CISCO Security Advisory
Published Date: Not specified
CVE: CVE-2026-76461
Advisory Summary
📅 September 14, 2026
🔐 ⛔ CISCO SECURE EMAIL GATEWAY SQL INJECTION — CRITICAL RISK
Cisco disclosed a Critical vulnerability in the email parsing component of Cisco AsyncOS running on Cisco Secure Email Gateway (ESA). An unauthenticated, remote attacker can send a crafted email that triggers SQL injection, potentially escalating to arbitrary command execution as root on the underlying operating system.
- Root cause: insufficient validation in ESA email parsing logic.
- Attack path: attacker delivers a malicious email containing SQL payloads to an affected ESA instance.
- Impact: execution of arbitrary SQL, which can lead to OS command execution with root privileges.
- The issue is internet-reachable in practice where ESA accepts inbound email from untrusted senders.
- Because there’s no workaround, exposure is primarily mitigated only by updating affected software and validating deployment configuration.
- Privilege level: root (maximum control of the appliance OS).
- Data center relevance: could enable persistent compromise, credential theft, mail routing manipulation, and broader network pivoting depending on host access.
✅ 🧯 Required actions (do this now)
1. Patch immediately: apply Cisco’s released software updates for this vulnerability.
2. Inventory affected systems: confirm which ESA/AsyncOS versions are deployed and whether they’re exposed to inbound email.
3. Hunt for compromise indicators: review mail processing logs for anomalous parser errors, unusual query-like patterns, or unexpected process execution (where logging is available).
4. Segment and limit access: ensure management interfaces (SSH/HTTPS) are not broadly exposed; restrict to trusted admin networks.
5. Verify update success: confirm services restart cleanly and that version/build numbers match Cisco’s fixed guidance.
- CVE: CVE-2026-76461
- Workaround: None provided
🔗
-2026-76461
Reference: Vendor Advisory