CVE-2026-39923 (CVSS 8.1)

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.

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CVSS v3.1 Score

8.1

HIGH

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H

Weakness Type (CWE)

CWE-324 CWE-324

References

Other References

https://github.com/flarum/framework/commit/2803058d0f9dc38252326070b46d4484fe5a857d https://github.com/flarum/framework/pull/4545 https://github.com/flarum/framework/releases/tag/v1.8.16 https://www.vulncheck.com/advisories/flarum-password-reset-token-expiry-bypass-via-post-reset

Frequently Asked Questions

What is 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. It has a CVSS v3.1 base score of 8.1 (HIGH).

How severe is CVE-2026-39923? +

CVE-2026-39923 has a CVSS v3.1 score of 8.1 out of 10, rated HIGH. This is a high-severity vulnerability that should be prioritized for patching.

How do I check if I'm vulnerable to CVE-2026-39923? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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CVE-2026-39923