Resource exhaustion in Discourse - CVE-2023-48297
Published: January 9, 2024 / Updated: July 1, 2026
Vulnerability identifier: #VU136092
CSH Severity: High
CVSS v4: 8.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2023-48297
CWE-ID: CWE-400
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to cause a denial of service.
The vulnerability exists due to uncontrolled resource consumption in message serializer when processing expanded chat mentions. A remote attacker can send content containing @all or @here mentions to cause a denial of service.
The issue is triggered by the full list of mentioned users being included in the serialized message data, which can result in a very large user array.
Affected software
Discourse
How to mitigate CVE-2023-48297
Install security update from vendor's website.
Discourse - addressed in versions 3.1.4, 3.2.0 beta4