OS Command Injection in Linksys WRT54GL Affected by Remote Exploitation
CVE-2026-121931

9.4CRITICAL

Key Information:

Vendor

Linksys
Status
Wrt54gl
Vendor
CVE Published:
4 November 2026

Badges

👾 Exploit Exists🟡 Public PoC

What is CVE-2026-121931?

A security flaw has been identified in the Linksys WRT54GL 4.30.18 that affects the Traceroute Diagnostic Function through the apply.cgi file. An attacker can exploit this vulnerability remotely by manipulating the 'traceroute_ip' argument, leading to unauthorized OS command execution. It’s important to note that this vulnerability is present in products that are no longer supported by the vendor, raising concerns for users regarding the exposure to potential attacks.

Affected Version(s)

WRT54GL 4.30.18

Exploit Proof of Concept (PoC)

PoC code is written by security researchers to demonstrate the vulnerability can be exploited. PoC code is also a key component for weaponization which could lead to ransomware.

CVE-2026-121931 - Proof of Concept

References

https://vuldb.com/vuln/431043
vdb-entrytechnical-description
https://vuldb.com/vuln/431043/cti
signaturepermissions-required
https://vuldb.com/cve/CVE-2026-121931
third-party-advisory

CVSS V4

Score:
9.4
Severity:
CRITICAL
Confidentiality:
High
Integrity:
High
Availability:
High
Attack Vector:
Network
Attack Complexity:
Low
Attack Required:
None
Privileges Required:
Undefined
User Interaction:
None

Timeline

  • 🟡

    Public PoC available

  • 👾

    Exploit known to exist

  • Vulnerability published

  • Vulnerability Reserved

Credit

liuyingqi (VulDB User)
VulDB CNA Team
.