MyTube: Improper Restriction of Excessive Authentication Attempts
CVE-2026-33935 is a high-severity improper restriction of excessive authentication attempts vulnerability in MyTube from Franklioxygen, with a CVSS 3.1 base score of 7.5 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. Affected MyTube versions: < 1.8.72. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.58% chance of exploitation within 30 days, which is low compared with other CVEs.
High severity with no evidence of exploitation so far.
What to do
- Check which version of MyTube you run against the affected versions below, and install the vendor's latest release.
- Read the advisory on github.com for workarounds and exact fixed builds.
- Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Franklioxygen | MyTube | < 1.8.72 | Not stated |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- NoneNo account or login is needed.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- NoneNo data is disclosed.
- Integrity
- NoneNothing can be modified.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 4.0 | 7.7 | High | CNA (github.com) |
| CVSS 3.1 | 7.5 | High | NVD |
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.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Improper Restriction of Excessive Authentication Attempts
The product does not implement sufficient measures to prevent multiple failed authentication attempts within a short time frame.
How developers prevent this class of flaw
- Common protection mechanisms include: Disconnecting the user after a small number of failed attempts Implementing a timeout Locking out a targeted account Requiring a computational task on the user's part.
- Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid. Consider using libraries with authentication capabilities such as OpenSSL or the ESAPI Authenticator.
More Improper Restriction of Excessive Authentication Attempts vulnerabilities (CWE-307)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: poc, automatable: no, technical impact: partial).
- Record last changed materially (score, affected products, status or references).
References
Patches and release notes
Other references
Other vulnerabilities in MyTube
- 8.7 High severity
- 7.1 High severity
- 9.8 Critical severity
- 8.8 High severity
- 9.8 Critical severity
Recent Improper Restriction of Excessive Authentication Attempts vulnerabilities
- 9.8 Critical severity
- 9.8 Critical severity
- 7.5 High severity
- 9.8 Critical severity
- 7.5 High severity
- 7.5 High severity
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