Vulnerability · Published Jul 9, 2026 · Assigned by GitHub_M
CVE-2026-59828Discourse: Hidden post revisions leak through adjacent visible diffs
Medium 5.3
In plain English
A medium-severity information exposure in discourse from discourse. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.5% (higher than 46% of all known vulnerabilities).
Severity (CVSS 3.1)5.3Medium
Exploit odds (30 days)0.5%top 54.1% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known
Official 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.
Affected products (as reported)
Weakness: CWE-200 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
References
- https://github.com/discourse/discourse/security/advisories/GHSA-q456-4f8q-42vx x_refsource_CONFIRM
- https://github.com/discourse/discourse/commit/1f26c1163ce87a2abbd1d01780ab1b5fb16e75f6 x_refsource_MISC
- https://github.com/discourse/discourse/commit/8b773332b0f937dfcd894ed56d56fc5a81578d9d x_refsource_MISC
- https://github.com/discourse/discourse/commit/8d36da1b68c906592abde3f2e94d505cdf097435 x_refsource_MISC
- https://github.com/discourse/discourse/commit/d58988d46bb1019bfa8b8330ae81a1a134e08511 x_refsource_MISC
- https://github.com/discourse/discourse/releases/tag/v2026.1.5 x_refsource_MISC
- https://github.com/discourse/discourse/releases/tag/v2026.4.2 x_refsource_MISC
- https://github.com/discourse/discourse/releases/tag/v2026.5.1 x_refsource_MISC
- https://github.com/discourse/discourse/releases/tag/v2026.6.0 x_refsource_MISC