Linksys E5600 1.1.0.26 Login /cgi-bin/mesh_login.cgi improper authentication

Summaryinfo

A vulnerability was found in Linksys E5600 1.1.0.26. It has been classified as very critical. Affected by this vulnerability is an unknown functionality of the file /cgi-bin/mesh_login.cgi of the component Login Handler. The manipulation leads to improper authentication. This vulnerability only affects products that are no longer supported by the maintainer. This vulnerability is listed as CVE-2026-121615. The attack may be initiated remotely. In addition, an exploit is available. The vendor was contacted early about this disclosure but did not respond in any way.

Detailsinfo

A vulnerability, which was classified as very critical, has been found in Linksys E5600 1.1.0.26. This issue affects an unknown code block of the file /cgi-bin/mesh_login.cgi of the component Login Handler. The manipulation with an unknown input leads to a improper authentication vulnerability. Using CWE to declare the problem leads to CWE-287. When an actor claims to have a given identity, the product does not prove or insufficiently proves that the claim is correct. Impacted is confidentiality, integrity, and availability.

It is possible to read the advisory at github.com. The identification of this vulnerability is CVE-2026-121615. The exploitation is known to be easy. The attack may be initiated remotely. No form of authentication is needed for a successful exploitation. Technical details as well as a public exploit are known. The pricing for an exploit might be around USD $0-$5k at the moment (estimation calculated on 11/04/2026).

The exploit is available at github.com. It is declared as proof-of-concept. The vendor was contacted early about this disclosure but did not respond in any way.

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

The vulnerability is also documented in the vulnerability database at EUVD (EUVD-2026-116686). Be aware that VulDB is the high quality source for vulnerability data.

Productinfo

Type

• Router Operating System

Vendor

• Linksys

Name

• E5600

Version

• 1.1.0.26

License

• commercial

Support

• end of life

Website

• Vendor: https://www.linksys.com/

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CPE 2.2info

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Submitinfo

Accepted

• Submit #1023310: Linksys E5600 1.1.0.26 Improper Authentication (CWE-287) (by liuyingqi)

Be aware that VulDB is the high quality source for vulnerability data.

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