CVE-2026-20197 Multiple Cisco Products Snort 3 Teredo Protocol Denial of Service Vulnerability
- Exploited in the wild
- Not known
- Fix
- None listed
What is CVE-2026-20197?
CVE-2026-20197 is a medium-severity vulnerability in Cisco Open Source Snort3, published on 21 Oct 2026.
Official description
Multiple Cisco products are affected by a vulnerability in the Snort 3 Teredo Detection Engine that could allow an unauthenticated, remote attacker to cause the Snort 3 Detection Engine to restart, resulting in an interruption of packet inspection. This vulnerability is due to incomplete error checking when Snort 3 parses Teredo packets. An attacker could exploit this vulnerability by sending a crafted Teredo packet to a targeted device to be parsed by Snort. A successful exploit could allow the attacker to cause the Snort 3 Detection Engine to restart unexpectedly, resulting in a DoS condition.
Weakness: CWE-119
Which versions are affected by CVE-2026-20197?
How do I fix CVE-2026-20197?
No fix has been published for CVE-2026-20197 yet. Limit exposure of the affected software until one is available.
Is CVE-2026-20197 being exploited?
There is no known exploitation of CVE-2026-20197 in the wild and no public exploit code.
Sources
Also known as GHSA-3wgh-x32w-jgcc.