Vulnerability in Flarum Framework
CVE-2026-39924
Flarum before 1.8.16 contains an improper session invalidation vulnerability that allows attackers who hold a valid session token to retain full account access after a victim changes their password, because the access_tokens table is never cleared on password change events. The TokensClearer::clearPasswordTokens() function only removes rows from the password_tokens table while leaving all active session cookies and API bearer tokens intact, including long-lived RememberAccessToken entries, and administrator-forced password resets via the user update endpoint are equally ineffective at revoking attacker-held sessions.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 6.8 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:N.
EPSS exploit prediction
EPSS: 0.004 (31.2th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 31st percentile — 31.2% 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/4546 (issue-tracking)
- github.com/flarum/framework/commit/5f080293a029d0d273eb9678d597c74ea86a3bcc (patch)
- www.vulncheck.com/advisories/flarum-session-persistence-via-improper-access-tok… (third-party-advisory)
Frequently asked questions
- What is CVE-2026-39924?
- CVE-2026-39924 is a medium-severity vulnerability in Flarum Framework, classified under Insufficient Session Expiration. CVSS score: 6.8/10. Published 2026-08-05.
- How severe is CVE-2026-39924?
- Medium severity. CVSS v3 base score is 6.8 out of 10.