CVE-2026-59828 Discourse: Hidden post revisions leak through adjacent visible diffs

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,...

PT-2026-57004

Name of the Vulnerable Software and Affected Versions Discourse versions prior to 2026.6.0 Discourse versions prior to 2026.5.1 Discourse versions prior to 2026.4.2 Discourse versions prior to 2026.1.5 Description Post revisions intended to be hidden from regular users may be leaked through visib...