Auth bypass in Discourse
CVE-2026-55704
Discourse is an open-source discussion platform. Prior o 2026.1.6, 2026.5.2, 2026.6.1, and 2026.7.0, users who were allowed to view a group’s activity, but were not permitted to see shared drafts, could still receive shared-draft entries through the group posts and group mentions endpoints. This could disclose shared-draft topic titles and post excerpt/content, resulting in an information disclosure of unpublished draft material. This issue is fixed in versions 2026.1.6, 2026.5.2, 2026.6.1, and 2026.7.0.
Vulnerability class: Broken Access Control
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 < 2026.1.6, >= 2026.5.0-latest, < 2026.5.2, >= 2026.6.0-latest, < 2026.6.1
Weakness classification (CWE)
References
- security-advisories@github.com (x_refsource_CONFIRM)
Frequently asked questions
- What is CVE-2026-55704?
- CVE-2026-55704 is a medium-severity vulnerability in Discourse, classified under Missing Authorization. CVSS score: 4.3/10. Published 2026-08-17.
- How severe is CVE-2026-55704?
- Medium severity. CVSS v3 base score is 4.3 out of 10.