Talishar Chat Message authKey improper authentication

Summaryinfo

A vulnerability has been found in Talishar and classified as critical. The affected element is an unknown function of the component Chat Message Handler. The manipulation of the argument authKey leads to improper authentication. This vulnerability is traded as CVE-2026-28428. It is possible to initiate the attack remotely. There is no exploit available. It is suggested to install a patch to address this issue.

Detailsinfo

A vulnerability was found in Talishar (the affected version unknown). It has been rated as critical. This issue affects an unknown part of the component Chat Message Handler. The manipulation of the argument authKey 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. The summary by CVE is:

Talishar is a fan-made Flesh and Blood project. Prior to commit a9c218e, an authentication bypass vulnerability in Talishar's game endpoint validation logic allows any unauthenticated attacker to perform authenticated game actions — including sending chat messages and submitting game inputs — by supplying an empty authKey parameter (authKey=). The server-side validation uses a loose comparison that accepts an empty string as a valid credential, while correctly rejecting non-empty but incorrect keys. This asymmetry means the authentication mechanism can be completely bypassed without knowing any valid token. This issue has been patched in commit a9c218e.

The advisory is shared at github.com. The identification of this vulnerability is CVE-2026-28428 since 02/27/2026. 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 are known, but no exploit is available.

Applying the patch a9c218efa37756c9e7eed056fbff6ee03f79aefc is able to eliminate this problem. The bugfix is ready for download at github.com.

The vulnerability is also documented in the vulnerability database at EUVD (EUVD-2026-9981). Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Productinfo

Name

• Talishar

License

• open-source

Website

• Product: https://github.com/Talishar/Talishar/

CPE 2.3info

• 🔒

CPE 2.2info

• 🔒

CVSSv4info

CVSSv3info

CVSSv2info

Exploitinginfo

Threat Intelligenceinfo

Countermeasuresinfo

Timelineinfo

Sourcesinfo

Entryinfo

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Discussion