Discourse: Hidden post revisions leak through adjacent visible diffs
13Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 5.3epss 0.5%
exploitation probability
0.5%top 55% of all CVEs
observed exploitation
nono source reports it
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.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
Affected products
discourse · discourseReferences
https://github.com/discourse/discourse/commit/1f26c1163ce87a2abbd1d01780ab1b5fb16e75f6https://github.com/discourse/discourse/commit/8b773332b0f937dfcd894ed56d56fc5a81578d9dhttps://github.com/discourse/discourse/commit/8d36da1b68c906592abde3f2e94d505cdf097435https://github.com/discourse/discourse/commit/d58988d46bb1019bfa8b8330ae81a1a134e08511https://github.com/discourse/discourse/releases/tag/v2026.1.5https://github.com/discourse/discourse/releases/tag/v2026.4.2https://github.com/discourse/discourse/releases/tag/v2026.5.1https://github.com/discourse/discourse/releases/tag/v2026.6.0https://github.com/discourse/discourse/security/advisories/GHSA-q456-4f8q-42vx