Improper access control in Discourse - CVE-2026-53960
Published: July 29, 2026
Vulnerability identifier: #VU139997
CSH Severity: Medium
CVSS v4.0: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:U/U:Green
CVE-ID: CVE-2026-53960
CWE-ID: CWE-284
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Affected software:
Discourse
Discourse
Detailed vulnerability description
The vulnerability allows a remote attacker to disclose sensitive information.
The vulnerability exists due to improper access control in the Q&A schema JSON-LD structured data generation when serving QAPage JSON-LD for topics with hidden or otherwise unviewable first-post content. A remote attacker can request the affected page to disclose sensitive information.
The leaked content was exposed to unauthenticated visitors and search-engine crawlers.
How to mitigate CVE-2026-53960
Install security update from vendor's website.