Cisco Adaptive Security Appliance Software and Firepower Threat Defense Software IPv6 DNS Denial of Service Vulnerability
Description
A crafted DNS query over IPv6 can cause Cisco ASA and FTD devices to reload, leading to a denial of service.
AI Insight
LLM-synthesized narrative grounded in this CVE's description and references.
A crafted DNS query over IPv6 can cause Cisco ASA and FTD devices to reload, leading to a denial of service.
Vulnerability
The vulnerability exists in DNS over IPv6 packet processing for Cisco Adaptive Security Appliance (ASA) Software and Firepower Threat Defense (FTD) Software. It is due to improper length validation of a field in an IPv6 DNS packet. Affected versions are detailed in the Cisco advisory [1].
Exploitation
An unauthenticated, remote attacker can exploit this vulnerability by sending a crafted DNS query over IPv6 that traverses the affected device. No authentication or user interaction is required [1].
Impact
Successful exploitation causes the device to unexpectedly reload, resulting in a denial of service (DoS) condition. The impact is limited to availability; no data compromise or code execution is involved [1].
Mitigation
Cisco has released free software updates to address this vulnerability. Customers should upgrade to fixed releases as indicated in the advisory [1]. No workarounds are mentioned.
AI Insight generated on May 25, 2026. Synthesized from this CVE's description and the cited reference URLs; citations are validated against the source bundle.
Affected products
3- Range: n/a
Patches
0No patches discovered yet.
Vulnerability mechanics
No source-code context for this CVE — mechanics is only generated when we can read the actual fix diff. Without that, the four sections (root cause, attack vector, affected code, fix) would be speculation rather than analysis.
References
1- tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-asaftd-ipv6-67pA658kmitrevendor-advisoryx_refsource_CISCO
News mentions
0No linked articles in our index yet.