Vulnerability in Flarum Framework
CVE-2026-39923
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.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 8.1 (High). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H.
EPSS exploit prediction
EPSS: 0.004 (37.1th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 37th percentile — 37.1% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.004 · newest: 0.004 · change: 0.000
Affected products
- Flarum Framework — versions 0
Weakness classification (CWE)
References
- github.com/flarum/framework/releases/tag/v1.8.16 (release-notes)
- github.com/flarum/framework/pull/4545 (issue-tracking)
- github.com/flarum/framework/commit/2803058d0f9dc38252326070b46d4484fe5a857d (patch)
- www.vulncheck.com/advisories/flarum-password-reset-token-expiry-bypass-via-post… (third-party-advisory)
Frequently asked questions
- What is CVE-2026-39923?
- CVE-2026-39923 is a high-severity vulnerability in Flarum Framework, classified under Use of a Key Past its Expiration Date. CVSS score: 8.1/10. Published 2026-08-05.
- How severe is CVE-2026-39923?
- High severity. CVSS v3 base score is 8.1 out of 10.