Description
Discourse is an open-source discussion platform. Prior to 2026.6.0, 2026.5.1, 2026.4.2, and 2026.1.5, post revisions that should be hidden from regular users could be leaked through visible diffs on adjacent revisions serialized by PostRevisionSerializer. This issue is fixed in versions 2026.6.0, 2026.5.1, 2026.4.2, and 2026.1.5.
Problem types
CWE-200: Exposure of Sensitive Information to an Unauthorized Actor
Product status
>= 2026.4.0-latest, < 2026.4.2
>= 2026.5.0-latest, < 2026.5.1
References
github.com/...course/security/advisories/GHSA-q456-4f8q-42vx
github.com/...ommit/1f26c1163ce87a2abbd1d01780ab1b5fb16e75f6
github.com/...ommit/8b773332b0f937dfcd894ed56d56fc5a81578d9d
github.com/...ommit/8d36da1b68c906592abde3f2e94d505cdf097435
github.com/...ommit/d58988d46bb1019bfa8b8330ae81a1a134e08511
github.com/discourse/discourse/releases/tag/v2026.1.5
github.com/discourse/discourse/releases/tag/v2026.4.2
github.com/discourse/discourse/releases/tag/v2026.5.1
github.com/discourse/discourse/releases/tag/v2026.6.0