Insufficient Session Expiration in Discourse - CVE-2025-53102
Published: July 1, 2026
Vulnerability identifier: #VU136108
CSH Severity: Low
CVSS v4.0: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N/E:U/U:Clear
CVE-ID: CVE-2025-53102
CWE-ID: CWE-613
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vendor: Civilized Discourse Construction Kit, Inc.
Affected software:
Discourse
Discourse
Detailed vulnerability description
The vulnerability allows a remote user to reuse a previously generated WebAuthn challenge.
The vulnerability exists due to improper session management in the WebAuthn challenge handling logic when processing two-factor authentication with a physical security key. A remote user can authenticate and reuse a previously generated challenge to reuse a previously generated WebAuthn challenge.
The issue occurs after successful authentication because the challenge is not cleared from the user's session.
How to mitigate CVE-2025-53102
Install security update from vendor's website.