CVE-2026-59828
Discourse: Hidden post revisions leak through adjacent visible diffs
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.
INFO
Published Date :
July 9, 2026, 10:17 p.m.
Last Modified :
July 13, 2026, 3:22 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | |||||
| CVSS 3.1 | MEDIUM | [email protected] |
Solution
- Update Discourse to version 2026.6.0 or later.
- Verify adjacent revision diffs are properly hidden.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-59828.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-59828 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-59828
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-59828 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-59828 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
Initial Analysis by [email protected]
Jul. 13, 2026
Action Type Old Value New Value Added CWE NVD-CWE-noinfo Added CPE Configuration OR *cpe:2.3:a:discourse:discourse:*:*:*:*:*:*:*:* versions from (including) 2026.1.0 up to (excluding) 2026.1.5 *cpe:2.3:a:discourse:discourse:*:*:*:*:*:*:*:* versions from (including) 2026.4.0 up to (excluding) 2026.4.2 *cpe:2.3:a:discourse:discourse:*:*:*:*:*:*:*:* versions from (including) 2026.5.0 up to (excluding) 2026.5.1 *cpe:2.3:a:discourse:discourse:2026.6.0:*:*:*:latest:*:*:* Added Reference Type GitHub, Inc.: https://github.com/discourse/discourse/commit/1f26c1163ce87a2abbd1d01780ab1b5fb16e75f6 Types: Patch Added Reference Type GitHub, Inc.: https://github.com/discourse/discourse/commit/8b773332b0f937dfcd894ed56d56fc5a81578d9d Types: Patch Added Reference Type GitHub, Inc.: https://github.com/discourse/discourse/commit/8d36da1b68c906592abde3f2e94d505cdf097435 Types: Patch Added Reference Type GitHub, Inc.: https://github.com/discourse/discourse/commit/d58988d46bb1019bfa8b8330ae81a1a134e08511 Types: Patch Added Reference Type GitHub, Inc.: https://github.com/discourse/discourse/releases/tag/v2026.1.5 Types: Release Notes Added Reference Type GitHub, Inc.: https://github.com/discourse/discourse/releases/tag/v2026.4.2 Types: Release Notes Added Reference Type GitHub, Inc.: https://github.com/discourse/discourse/releases/tag/v2026.5.1 Types: Release Notes Added Reference Type GitHub, Inc.: https://github.com/discourse/discourse/releases/tag/v2026.6.0 Types: Release Notes Added Reference Type GitHub, Inc.: https://github.com/discourse/discourse/security/advisories/GHSA-q456-4f8q-42vx Types: Vendor Advisory -
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Jul. 10, 2026
Action Type Old Value New Value Added SSVC {'id': 'CVE-2026-59828', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'none'}, {'automatable': 'yes'}, {'technicalImpact': 'partial'}], 'version': '2.0.3', 'timestamp': '2026-07-10T14:17:36.503953Z'} -
New CVE Received by [email protected]
Jul. 09, 2026
Action Type Old Value New Value Added Affected [{'vendor': 'discourse', 'product': 'discourse', 'versions': [{'status': 'affected', 'version': '>= 2026.1.0-latest, < 2026.1.5'}, {'status': 'affected', 'version': '>= 2026.4.0-latest, < 2026.4.2'}, {'status': 'affected', 'version': '>= 2026.5.0-latest, < 2026.5.1'}]}] Added 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. Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N Added CWE CWE-200 Added Reference https://github.com/discourse/discourse/commit/1f26c1163ce87a2abbd1d01780ab1b5fb16e75f6 Added Reference https://github.com/discourse/discourse/commit/8b773332b0f937dfcd894ed56d56fc5a81578d9d Added Reference https://github.com/discourse/discourse/commit/8d36da1b68c906592abde3f2e94d505cdf097435 Added Reference https://github.com/discourse/discourse/commit/d58988d46bb1019bfa8b8330ae81a1a134e08511 Added Reference https://github.com/discourse/discourse/releases/tag/v2026.1.5 Added Reference https://github.com/discourse/discourse/releases/tag/v2026.4.2 Added Reference https://github.com/discourse/discourse/releases/tag/v2026.5.1 Added Reference https://github.com/discourse/discourse/releases/tag/v2026.6.0 Added Reference https://github.com/discourse/discourse/security/advisories/GHSA-q456-4f8q-42vx