Auth bypass in Discourse
CVE-2025-58055
Discourse is an open-source community discussion platform. In versions 3.5.0 and below, the Discourse AI suggestion endpoints for topic “Title”, “Category”, and “Tags” allowed authenticated users to extract information about topics that they weren’t authorized to access. By modifying the “topic_id” value in API requests to the AI suggestion endpoints, users could target specific restricted topics. The AI model’s responses then disclosed information that the authenticated user couldn’t normally access. This issue is fixed in version 3.5.1. To workaround this issue, users can restrict group access to the AI helper feature through the "composer_ai_helper_allowed_groups" and "post_ai_helper_allowed_groups" site settings.
EPSS: 0.002 (14.9th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 4.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N.
Affected products
- Discourse — versions 3.6.0, < 3.5.1
Weakness classification (CWE)
Public proof-of-concept exploits
References
- security-advisories@github.com (x_refsource_CONFIRM, Vendor Advisory)
- security-advisories@github.com (Patch, x_refsource_MISC)
- af854a3a-2127-422b-91ae-364da2661108
- af854a3a-2127-422b-91ae-364da2661108
Frequently asked questions
- What is CVE-2025-58055?
- CVE-2025-58055 is a medium-severity vulnerability in Discourse, classified under Improper Access Control. CVSS score: 4.3/10. Published 2025-10-01.
- How severe is CVE-2025-58055?
- Medium severity. CVSS v3 base score is 4.3 out of 10.
- Is CVE-2025-58055 known to be exploited?
- 1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.