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.
EPSS: 0.003 (18.2th percentile) — read the EPSS interpretation.
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.
Affected products
- Flarum Framework — versions 0
Weakness classification (CWE)
References
- disclosure@vulncheck.com (release-notes)
- disclosure@vulncheck.com (issue-tracking)
- disclosure@vulncheck.com (patch)
- disclosure@vulncheck.com (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.