Cisco ASA and FTD Flaw Exploited in the Wild Can Trigger Remote DoS
Summary: Cisco warned that CVE-2026-20349, a high-severity (CVSS 8.6) insufficient error-checking flaw in Secure Firewall ASA and FTD Software, has been exploited in the wild, allowing an unauthenticated remote attacker to send a crafted HTTP request to the Remote Access SSL VPN service and cause the device to reload. Cisco said it became aware of active exploitation earlier this month, found the issue during internal security testing, credited Valerio Brussani for separately reporting it, and noted there are no workarounds; CISA added the flaw to its KEV catalog with an August 14, 2026 fix deadline for FCEB agencies.
What you should know: An unauthenticated attacker can force a firewall or VPN gateway to reload with a single crafted HTTP request, and Cisco has no workaround to offer - so the only remedy is patching before the August 14, 2026 federal deadline, with no public detail yet on who is exploiting it or which organizations were hit.
Read the original at The Hacker News ↗
- Topics
- Threat Actors & Nation-State
- Mentions
- CVE-2026-20349
- Related
- CVE-2026-20349: Cisco Secure Firewall Adaptive Security Appliance (ASA) and Secure Firewall Threat Defense (FTD) Heap Inspection Vulnerability Known Exploited Vulnerabilities · Aug 11, 2026