CVE-2026-121931 — Zimo-666
CRITICALCVE-2026-121931 is a critical-severity (CVSS 9.1) CWE-77 vulnerability. The records list no fixed version yet; check the vendor advisory below and apply the mitigations in the meantime.
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.…
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.
Detection & mitigation playbook
VulnerabilityDetect
Identify every host running the affected component and compare the installed build against the fixed version below — for source-built or distro-packaged software the version string, not a lockfile, is the source of truth (`dpkg -l`, `rpm -q`, or the binary's own `--version`).
Remediation status
The records we use list no fixed release for CVE-2026-121931. Check the upstream advisory for a patched version, and apply the exposure-reduction steps below in the meantime.
Mitigate without a patch
Stop passing untrusted input into the interpreter or shell: call the affected binary with an argument array rather than a composed command string, reject anything outside a strict allowlist of expected values, and run the component under an account that cannot reach beyond the work it legitimately does.
Frequently Asked Questions
Is CVE-2026-121931 in your dependencies?
Find it across your dependency tree, including transitive dependencies.