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.
History

Wed, 28 Jan 2026 19:00:00 +0000

Type Values Removed Values Added
Description 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.
Title Discourse has DoS vulnerability in username change endpoint
Weaknesses CWE-770
References
Metrics cvssV3_1

{'score': 4.3, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L'}


cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published:

Updated: 2026-01-28T20:20:41.258Z

Reserved: 2025-12-22T17:55:15.946Z

Link: CVE-2025-68659

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-01-28T19:16:23.563

Modified: 2026-01-28T19:16:23.563

Link: CVE-2025-68659

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

No data.