Information disclosure in Discourse
CVE-2026-49256
Discourse is an open-source discussion platform. Prior to 2026.6.0, 2026.5.1, 2026.4.2, and 2026.1.5, restricted tag and tag-group names attached to publicly readable categories as allowed_tags, allowed_tag_groups, or required tag groups could leak to anonymous and unauthorized users through category and group endpoints. This issue is fixed in versions 2026.6.0, 2026.5.1, 2026.4.2, and 2026.1.5.
Vulnerability class: Information Disclosure
EPSS: 0.004 (30.6th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N.
Affected products
- Discourse — versions >= 2026.5.0-latest, < 2026.5.1, >= 2026.4.0-latest, < 2026.4.2, 2026.6.0
Weakness classification (CWE)
References
- security-advisories@github.com (Patch, x_refsource_MISC, Release Notes)
- security-advisories@github.com (x_refsource_MISC, Release Notes)
- security-advisories@github.com (x_refsource_MISC, Release Notes)
- security-advisories@github.com (x_refsource_MISC, Release Notes)
- security-advisories@github.com (x_refsource_CONFIRM, Mitigation, Vendor Advisory)
Frequently asked questions
- What is CVE-2026-49256?
- CVE-2026-49256 is a high-severity vulnerability in Discourse, classified under Information Disclosure. CVSS score: 7.5/10. Published 2026-07-09.
- How severe is CVE-2026-49256?
- High severity. CVSS v3 base score is 7.5 out of 10.