CVE-2025-24806
Regulation applies separately to Username-based logins to Email-based logins in authelia
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
Blast Radius
github.com/authelia/authelia/v4Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects Go packages — download data is not available via public APIs for these ecosystems.
Description
Authelia is an open-source authentication and authorization server providing two-factor authentication and single sign-on (SSO) for applications via a web portal. If users are allowed to sign in via both username and email the regulation system treats these as separate login events. This leads to the regulation limitations being effectively doubled assuming an attacker using brute-force to find a user password. It's important to note that due to the effective operation of regulation where no user-facing sign of their regulation ban being visible either via timing or via API responses, it's effectively impossible to determine if a failure occurs due to a bad username password combination, or a effective ban blocking the attempt which heavily mitigates any form of brute-force. This occurs because the records and counting process for this system uses the method utilized for sign in rather than the effective username attribute. This has a minimal impact on account security, this impact is increased naturally in scenarios when there is no two-factor authentication required and weak passwords are used. This makes it a bit easier to brute-force a password. A patch for this issue has been applied to versions 4.38.19, and 4.39.0. Users are advised to upgrade. Users unable to upgrade should 1. Not heavily modify the default settings in a way that ends up with shorter or less frequent regulation bans. The default settings effectively mitigate any potential for this issue to be exploited. and 2. Disable the ability for users to login via an email address.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐹Go | github.com/authelia/authelia/v4 | all versions | 4.38.19 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/authelia/authelia/v4. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update github.com/authelia/authelia/v4 to 4.38.19 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2025-24806 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether CVE-2025-24806 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to CVE-2025-24806. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2025-24806 in your dependencies?
O3 detects CVE-2025-24806 across Go dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.