Authorization bypass through user-controlled key in Forum - CVE-2026-77143
Published: August 26, 2026
Vulnerability identifier: #VU145752
CSH Severity: High
CVSS v4: 8.8 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:H/VA:N/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-77143
CWE-ID: CWE-639
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to compromise the target system.
The vulnerability exists due to the frontend topic editing flow does not verify on the server side that the requesting visitor owns the topic being modified. A remote attacker can submit a modified update request for that topic directly and overwrite its content.
Affected software
Forum
How to mitigate CVE-2026-77143
Install updates from vendor's website.
Forum - addressed in versions 4.0.4, 5.0.1, 6.2.4