Improper access control in Discourse - CVE-2026-33424
Published: July 1, 2026
Vulnerability identifier: #VU136286
CSH Severity: Low
CVSS v4.0: CVSS:4.0/AV:A/AC:L/AT:P/PR:H/UI:A/VC:H/VI:H/VA:L/SC:N/SI:N/SA:N/E:U/U:Clear
CVE-ID: CVE-2026-33424
CWE-ID: CWE-284
Exploitation vector: Adjecent network
Exploit availability:
No public exploit available
Vendor: Civilized Discourse Construction Kit, Inc.
Affected software:
Discourse
Discourse
Detailed vulnerability description
The vulnerability allows a remote privileged user to disclose sensitive information and modify access to a private message topic.
The vulnerability exists due to improper access control in the private message invite mechanism when handling invites after access to the private message has been revoked. A remote privileged user can send an invite to grant access to the private message topic to disclose sensitive information and modify access to a private message topic.
User interaction is required to accept the invite.
How to mitigate CVE-2026-33424
Install security update from vendor's website.