Medium severity · published Jul 9, 2026
CVE-2026-59828
Discourse: Hidden post revisions leak through adjacent visible diffs
5.3
CVSS
0.5%
EPSS
No
On KEV
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.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
Low
Integrity
None
Availability
None
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.5% · higher than 46% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
DI
discourse · discourse
>= 2026.1.0-latest, < 2026.1.5; >= 2026.4.0-latest, < 2026.4.2; >= 2026.5.0-latest, < 2026.5.1 · source: vendor, NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-59828
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-59828
Patch
https://github.com/discourse/discourse/commit/1f26c1163ce87a2abbd1d01780ab1b5fb16e75f6
Patch
https://github.com/discourse/discourse/commit/8b773332b0f937dfcd894ed56d56fc5a81578d9d
Patch
https://github.com/discourse/discourse/commit/8d36da1b68c906592abde3f2e94d505cdf097435
Patch
https://github.com/discourse/discourse/commit/d58988d46bb1019bfa8b8330ae81a1a134e08511
Release Notes
https://github.com/discourse/discourse/releases/tag/v2026.1.5
Release Notes
https://github.com/discourse/discourse/releases/tag/v2026.4.2
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