CVE-2026-20250: Missing Release of Resource after Effective Lifetime in Cisco Cisco Secure Firewall Adaptive Security Appliance (ASA) Software
A vulnerability in Datagram TLS (DTLS) message handling of Cisco Secure Firewall Adaptive Security Appliance (ASA) Software and Cisco Secure Firewall Threat Defense (FTD) Software for Cisco Secure Firewall 3100 Series and 4200 Series devices could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. This vulnerability is due to improper resource management when processing certain DTLS messages. An attacker could exploit this vulnerability by sending a crafted stream of DTLS traffic to an affected device. A successful exploit could allow the attacker to cause the device to reload, resulting in a DoS condition.
AI Analysis
Technical Summary
This vulnerability arises from improper release of resources after processing certain DTLS messages in Cisco Secure Firewall ASA and FTD software on 3100 and 4200 Series devices. An attacker can exploit this by sending a crafted stream of DTLS traffic, causing resource exhaustion that leads to device reload and denial of service. The vulnerability affects multiple specific software versions of Cisco ASA and FTD, with a CVSS 3.1 score of 8.6 indicating high severity. There is no indication of known exploits in the wild or vendor-provided patch information in the provided data.
Potential Impact
An unauthenticated remote attacker can cause a denial of service condition by triggering a device reload through crafted DTLS traffic. This disrupts network security operations relying on the affected Cisco firewall devices, potentially impacting availability but not confidentiality or integrity.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until a fix is available, consider limiting exposure of affected devices to untrusted networks and monitoring for unusual DTLS traffic patterns. Follow Cisco's official advisories for updates on patches or workarounds.
CVE-2026-20250: Missing Release of Resource after Effective Lifetime in Cisco Cisco Secure Firewall Adaptive Security Appliance (ASA) Software
Description
A vulnerability in Datagram TLS (DTLS) message handling of Cisco Secure Firewall Adaptive Security Appliance (ASA) Software and Cisco Secure Firewall Threat Defense (FTD) Software for Cisco Secure Firewall 3100 Series and 4200 Series devices could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. This vulnerability is due to improper resource management when processing certain DTLS messages. An attacker could exploit this vulnerability by sending a crafted stream of DTLS traffic to an affected device. A successful exploit could allow the attacker to cause the device to reload, resulting in a DoS condition.
CVSS v3.1
Score 8.6high
Affected software
Cisco
Cisco Secure Firewall Adaptive Security Appliance (ASA) Software
Cisco
Cisco Secure Firewall Threat Defense (FTD) Software
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
This vulnerability arises from improper release of resources after processing certain DTLS messages in Cisco Secure Firewall ASA and FTD software on 3100 and 4200 Series devices. An attacker can exploit this by sending a crafted stream of DTLS traffic, causing resource exhaustion that leads to device reload and denial of service. The vulnerability affects multiple specific software versions of Cisco ASA and FTD, with a CVSS 3.1 score of 8.6 indicating high severity. There is no indication of known exploits in the wild or vendor-provided patch information in the provided data.
Potential Impact
An unauthenticated remote attacker can cause a denial of service condition by triggering a device reload through crafted DTLS traffic. This disrupts network security operations relying on the affected Cisco firewall devices, potentially impacting availability but not confidentiality or integrity.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until a fix is available, consider limiting exposure of affected devices to untrusted networks and monitoring for unusual DTLS traffic patterns. Follow Cisco's official advisories for updates on patches or workarounds.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- cisco
- Date Reserved
- 2025-10-08T11:59:15.401Z
- Cvss Version
- 3.1
- State
- PUBLISHED
Threat ID: 6aab006855bf5e2cf523200a
Added to database: 09/16/2026, 20:47:36 UTC
Last enriched: 09/16/2026, 21:18:58 UTC
Last updated: 09/17/2026, 02:01:24 UTC
Views: 3
Community Reviews
0 reviewsCrowdsource mitigation strategies, share intel context, and vote on the most helpful responses. Sign in to add your voice and help keep defenders ahead.
Want to contribute mitigation steps or threat intel context? Sign in or create an account to join the community discussion.
Actions
Updates to AI analysis require Pro Console access. Upgrade inside Console → Billing.
External Links
Need more coverage?
Upgrade to Pro Console for AI refresh and higher limits.
For incident response and remediation, OffSeq services can help resolve threats faster.
Latest Threats
Check if your credentials are on the dark web
Instant breach scanning across billions of leaked records. Free tier available.