CVE-2026-121931 Linksys WRT54GL Traceroute Diagnostic Function apply.cgi system os command injection
- Exploited in the wild
- Not known
- Fix
- None listed
What is CVE-2026-121931?
CVE-2026-121931 is a critical vulnerability in Linksys WRT54GL, published on 4 Nov 2026.
Official description
A security vulnerability has been detected in Linksys WRT54GL 4.30.18. The impacted element is the function system of the file apply.cgi of the component Traceroute Diagnostic Function. Such manipulation of the argument traceroute_ip leads to os command injection. The attack can be launched remotely. The exploit has been disclosed publicly and may be used. The vendor was contacted early about this disclosure but did not respond in any way. This vulnerability only affects products that are no longer supported by the maintainer.
Which versions are affected by CVE-2026-121931?
How do I fix CVE-2026-121931?
No fix has been published for CVE-2026-121931 yet. Limit exposure of the affected software until one is available.
Is CVE-2026-121931 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-121931 exists.
Sources
Also known as GHSA-7p5v-44wr-v953.