CVE-2026-33935 MyTube has Unauthenticated Account Lockout via Shared Login Attempt State
Unauthenticated attackers can lock out all users by triggering failed logins on shared endpoints, causing indefinite denial of service.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-33935?
CVE-2026-33935 is a high-severity denial of service vulnerability in franklioxygen MyTube, published on 27 Mar 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
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.
Weakness: CWE-307
Which versions are affected by CVE-2026-33935?
It affects 1 product.
Products include Franklioxygen Mytube.
How do I fix CVE-2026-33935?
No fix has been published for CVE-2026-33935 yet. Limit exposure of the affected software until one is available.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2026-33935 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-33935 exists.
Other vulnerabilities in franklioxygen MyTube
- CVE-2026-23837 MyTube has an Authorization Bypass vulnerability
- CVE-2026-33890 MyTube has an Unauthenticated Admin Privilege Escalation via Passkey Registration
- CVE-2026-24139 MyTube Allows Unauthorized Database Export by Guest Users
- CVE-2026-33735 MyTube has an Improper Access Control that Allows Complete Application Takeover
- CVE-2026-23848 MyTube has Rate Limiting Bypass via X-Forwarded-For Header Spoofing
Sources
Also known as GHSA-6w95-qgc4-5jxf.