CVE-2026-39923 Flarum < 1.8.16 Password Reset Token Expiry Bypass via POST /reset
Unauthenticated attackers can reuse expired password reset tokens to change any user's password and gain account access.
- 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-2026-39923?
CVE-2026-39923 is a critical authentication bypass vulnerability in Flarum Framework, published on 5 Aug 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
Flarum before 1.8.16 contains a password reset token expiry bypass vulnerability that allows unauthenticated attackers to reuse expired password reset tokens by submitting them directly to the reset processing endpoint. The SavePasswordController::handle() method calls PasswordToken::findOrFail() without performing any expiry validation, allowing attackers to bypass the 24-hour token lifetime enforced only during form rendering and change any account's password to gain an authenticated session.
Weakness: CWE-324
Which versions are affected by CVE-2026-39923?
How do I fix CVE-2026-39923?
No fix has been published for CVE-2026-39923 yet. Limit exposure of the affected software until one is available.
Upgrade, and rotate credentials and sessions that may have been exposed. More about Authentication bypass.
Is CVE-2026-39923 being exploited?
There is no known exploitation of CVE-2026-39923 in the wild and no public exploit code.
Sources
Also known as GHSA-3mr9-883x-4f3x.