CVE-2026-33935MyTube has Unauthenticated Account Lockout via Shared Login Attempt State

Official description

MyTube is a self-hosted downloader and player for several video websites Prior to version 1.8.72, an unauthenticated attacker can lock out administrator and visitor accounts from password-based authentication by triggering failed login attempts. The application exposes three password verification endpoints, all of which are publicly accessible. All three endpoints share a single file-backed login attempt state stored in `login-attempts.json`. When any endpoint records a failed authentication attempt via `recordFailedAttempt()`, the shared login attempt state is updated, increasing the `failedAttempts` counter and adjusting the associated timestamps and cooldown values. Before verifying a password, each endpoint calls `canAttemptLogin()`. This function checks the shared JSON file to determine whether a cooldown period is active. If the cooldown has not expired, the request is rejected before the password is validated. Because the failed attempt counter and cooldown timer are globally shared, failed authentication attempts against any endpoint affect all other endpoints. An attacker can exploit this by repeatedly sending invalid authentication requests to any of these endpoints, incrementing the shared counter and waiting for the cooldown period between attempts. By doing so, the attacker can progressively increase the lockout duration until it reaches 24 hours, effectively preventing legitimate users from authenticating. Once the maximum lockout is reached, the attacker can maintain the denial of service indefinitely by waiting for the cooldown to expire and sending another failed attempt, which immediately triggers another 24-hour lockout if no successful login occurred in the meantime. Version 1.8.72 fixes the vulnerability.

Affected products (as reported)

References

• https://github.com/franklioxygen/MyTube/security/advisories/GHSA-6w95-qgc4-5jxf x_refsource_CONFIRM
• https://github.com/franklioxygen/MyTube/commit/4d89b146b16d08f27d8fd3e0a9122b109335deb1 x_refsource_MISC
• https://github.com/franklioxygen/MyTube/commit/752bc7f0ac83df8c881e6b6d5dd6f36bb274ee58 x_refsource_MISC
• https://github.com/franklioxygen/MyTube/commit/dd7b4a611fcc5b25a569f379be9a503eb413b6aa x_refsource_MISC
• https://github.com/franklioxygen/MyTube/blob/941035909ee3f96a6f80f38acf70cbc3e66b5098/backend/src/services/loginAttemptService.ts#L13 x_refsource_MISC