CVE-2026-72722
Published:August 10, 2026
Updated:August 31, 2026
Discourse is an open-source discussion platform. Prior to 2026.1.6, 2026.5.2, 2026.6.1, and 2026.7.0, TopicLink.extract_from, TopicLink.ensure_entry_for, and TopicLink.duplicate_lookup do not consistently enforce Guardian.can_see? checks when processing internal links. An authenticated user can submit links to restricted topics, private messages, or hidden posts and receive canonicalized slugs or titles in the composer_messages duplicate_lookup response even though the targets are not visible to that user. This issue is fixed in versions 2026.1.6, 2026.5.2, 2026.6.1, and 2026.7.0.
Affected Packages
https://github.com/discourse/discourse.git (GITHUB):
Affected version(s) >=v2026.5.0 <v2026.5.2Fix Suggestion:
Update to version v2026.5.2https://github.com/discourse/discourse.git (GITHUB):
Affected version(s) =v2026.6.0 <v2026.6.1Fix Suggestion:
Update to version v2026.6.1https://github.com/discourse/discourse.git (GITHUB):
Affected version(s) >=v2026.1.0 <v2026.1.6Fix Suggestion:
Update to version v2026.1.6https://github.com/discourse/discourse.git (GITHUB):
Affected version(s) >=v0.8.0 <v2026.7.0Fix Suggestion:
Update to version v2026.7.0Related Resources (11)
Do you need more information?
Contact UsCVSS v4
Base Score:
5.3
Attack Vector
NETWORK
Attack Complexity
LOW
Attack Requirements
NONE
Privileges Required
LOW
User Interaction
NONE
Vulnerable System Confidentiality
LOW
Vulnerable System Integrity
NONE
Vulnerable System Availability
NONE
Subsequent System Confidentiality
NONE
Subsequent System Integrity
NONE
Subsequent System Availability
NONE
CVSS v3
Base Score:
4.3
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
LOW
Integrity
NONE
Availability
NONE
Weakness Type (CWE)
Missing Authorization
EPSS
Base Score:
0.32