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Vulnerability · Published Nov 4, 2026 · Assigned by VulDB

CVE-2026-121931Linksys WRT54GL Traceroute Diagnostic Function apply.cgi system os command injection

Critical 9.1

In plain English

A critical-severity OS command injection in WRT54GL from Linksys. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 2.7% (higher than 86% of all known vulnerabilities).

Severity (CVSS 3.1)9.1Critical
Exploit odds (30 days)2.7%top 13.9% of all CVEs
Exploited in the wildNo reportsnot in CISA KEV
Attack toolingNoneno public tooling known

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.

Affected products (as reported)

VendorProductVersions
Linksys WRT54GL 4.30.18

Weakness: CWE-78, CWE-77 · Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H/E:P/RL:X/RC:C

References