CVE-2025-68659
January 28, 2026
Discourse is an open source discussion platform. Versions prior to 3.5.4, 2025.11.2, 2025.12.1, and 2026.1.0 have an application level denial of service vulnerabilityin the username change functionality at try.discourse.org. The vulnerability allows attackers to cause noticeable server delays and resource exhaustion by sending large JSON payloads to the username preference endpoint PUT /u//preferences/username, resulting in degraded performance for other users and endpoints. This issue is patched in versions 3.5.4, 2025.11.2, 2025.12.1, and 2026.1.0. No known workarounds are available.
Affected Packages
https://github.com/discourse/discourse.git (GITHUB):
Affected version(s) >=v0.8.0 <v3.5.4Fix Suggestion:
Update to version v3.5.4https://github.com/discourse/discourse.git (GITHUB):
Affected version(s) >=v2026.1.0 <v2026.1.0Fix Suggestion:
Update to version v2026.1.0https://github.com/discourse/discourse.git (GITHUB):
Affected version(s) =v2025.12.0-latest <v2025.12.0Fix Suggestion:
Update to version v2025.12.0https://github.com/discourse/discourse.git (GITHUB):
Affected version(s) >=v2025.11.0 <v2025.11.2Fix Suggestion:
Update to version v2025.11.2Related Resources (1)
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
NONE
Vulnerable System Integrity
NONE
Vulnerable System Availability
LOW
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
NONE
Integrity
NONE
Availability
LOW
Weakness Type (CWE)
Allocation of Resources Without Limits or Throttling
EPSS
Base Score:
0.05
