What’s Vulnerable › Vulnerabilities

CVE-2026-28428: Talishar: Authentication Bypass via Empty authKey Parameter Allows Unauthenticated Game Actions

• Severity: medium (CVSS 5.3 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.3% probability of exploitation in the next 30 days
• Public exploit or detection template: yes
• Published: 2026-03-06 · updated 2026-06-17
• Weakness: CWE-287

Description

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.

Affected products

• Talishar: before 2026-02-22 — fixed in 2026-02-22

How to fix

Upgrade to a fixed version: Talishar 2026-02-22. Check the vendor advisory for mitigations.

References

• https://github.com/Talishar/Talishar/commit/a9c218efa37756c9e7eed056fbff6ee03f79aefc
• https://github.com/Talishar/Talishar/security/advisories/GHSA-2659-p579-wv83

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