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No exploitation reported

CVE-2026-121931

Linksys WRT54GL Traceroute Diagnostic Function apply.cgi system os command injection

No exploitation reported by the sources we read.

  • Published2026-11-04
  • WeaknessCWE-77 · CWE-78

Am I affected?

With a domain, we read the version its public headers and pages expose. A distribution build can carry the fix under an older number.

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.

Timeline

dates in UTC
  1. 2026-11-0418:45CVE publishedCNA

Versions per branch

Products declared by the CNA

As VulDB, the CNA that assigned this CVE, declared them in the CVE record; versions as written. NVD lists no product for this CVE yet: this is the only product data so far.

  • Linksys WRT54GL
    Affected
    • = 4.30.18no fix stated

Source: the CNA record (CVE Program), © The MITRE Corporation,CVE Terms of UseCVE recordupdated 2026-11-04

Neither OSV.dev nor the vendor advisories we read list affected versions for CVE-2026-121931 yet.

Full record on NVD

Fix

No fix published by the sources we read yet. NVD record

Detection

Nuclei template
none so far
ProjectDiscovery
Exploit-DB
no entry
Exploit-DB
Metasploit modules
none listed
Metasploit Framework

Sources

  • CNACVSS 4.09.42026-11-04
  • CNACVSS 3.19.12026-11-04
  • NVDCVSS 3.19.1read 2026-11-04
  • CNACVSS 3.09.12026-11-04
  • CNACVSS 2.08.32026-11-04
  • CNAweakness (CWE)CWE-77, CWE-782026-11-04
  • NVDweakness (CWE)CWE-77, CWE-78read 2026-11-04

Identifiers

Technical details

CVSS v3 Vector
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H
CVSS 4.0 vector
CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/E:P/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Published
2026-11-04
Last Modified
2026-11-04
NVD status
Deferred

Frequently asked questions

What is CVE-2026-121931?

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.

Is CVE-2026-121931 actively exploited?

Active exploitation of CVE-2026-121931 has not been confirmed.

What is the CVSS score for CVE-2026-121931?

CVE-2026-121931 has a CVSS v3 base score of 9.1 (CRITICAL severity), with vector string CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H.

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