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.

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 SavePasswordCon…

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)

CWE-324 — Use of a Key Past its Expiration Date

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.