Information disclosure in Discourse
CVE-2026-47264
Discourse is an open-source discussion platform. From versions 2026.1.0-latest to before 2026.1.4, 2026.3.0-latest to before 2026.3.1, and 2026.4.0-latest to before 2026.4.1, DetailedTagSerializer#tag_group_names returned every tag group a tag belonged to without filtering against the requesting user's visibility. With SiteSetting.tags_listed_by_group enabled, anonymous and unprivileged users hitting TagsController#info (which is exempt from requires_login) could read the names of tag groups restricted to specific user groups or non-visible categories. This issue has been patched in versions 2026.1.4, 2026.3.1, 2026.4.1, and 2026.5.0-latest.1.
Vulnerability class: Information Disclosure
EPSS: 0.002 (12.0th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 5.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N.
Affected products
- Discourse — versions >= 2026.4.0-latest, < 2026.4.1, 2026.5.0, >= 2026.3.0-latest, < 2026.3.1
Weakness classification (CWE)
References
- security-advisories@github.com (x_refsource_CONFIRM, Third Party Advisory)
Frequently asked questions
- What is CVE-2026-47264?
- CVE-2026-47264 is a medium-severity vulnerability in Discourse, classified under Information Disclosure. CVSS score: 5.3/10. Published 2026-06-12.
- How severe is CVE-2026-47264?
- Medium severity. CVSS v3 base score is 5.3 out of 10.