Improper Authentication Vulnerability in Linksys E5600 Router
CVE-2026-121615

10CRITICAL

Key Information:

Vendor

Linksys
Status
E5600
Vendor
CVE Published:
4 November 2026

Badges

👾 Exploit Exists🟡 Public PoC

What is CVE-2026-121615?

A vulnerability has been identified in the Linksys E5600 router, specifically within the login handler component located at /cgi-bin/mesh_login.cgi. This flaw allows for exploitation through improper authentication methods, enabling malicious actors to potentially access the system without proper credentials. This vulnerability can be exploited remotely, increasing the risk as it affects devices that are no longer supported by the vendor. Recent disclosures indicate the attack vector is actively known, and users are encouraged to take immediate precautions against the potential for unauthorized access.

Affected Version(s)

E5600 1.1.0.26

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-2026-121615 - Proof of Concept

References

https://vuldb.com/vuln/430463
vdb-entry
https://vuldb.com/vuln/430463/cti
signaturepermissions-required
https://vuldb.com/cve/CVE-2026-121615
third-party-advisory

CVSS V4

Score:
10
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
.