CVE-2025-68659

Unknown Unknown - Not Provided

BaseFortify

Publication date: 2026-01-28

Last updated on: 2026-01-30

Assigner: GitHub, Inc.

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.

CVSS Scores

EPSS Scores

Probability:
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Meta Information

Published

2026-01-28

Last Modified

2026-01-30

Generated

2026-07-06

AI Q&A

2026-01-29

EPSS Evaluated

2026-07-05

NVD

CVE-2025-68659

EUVD

EUVD-2025-206425

Affected Vendors & Products

Vendor	Product	Version / Range
discourse	discourse	to 3.5.4 (exc)
discourse	discourse	From 2025.11.0 (inc) to 2025.11.2 (exc)
discourse	discourse	2025.12.0
discourse	discourse	2026.1.0

Helpful Resources

Exploitability

CWE

KEV

CWE ID	Description
CWE-770	The product allocates a reusable resource or group of resources on behalf of an actor without imposing any intended restrictions on the size or number of resources that can be allocated.

Attack-Flow Graph

Executive Summary

This vulnerability is an application-level denial of service issue in Discourse's username change functionality. Attackers can send large JSON payloads to the username preference endpoint (PUT /u//preferences/username) on try.discourse.org, causing server delays and resource exhaustion. This results in degraded performance for other users and endpoints.

Impact Analysis

The vulnerability can cause noticeable server delays and resource exhaustion, leading to degraded performance of the Discourse platform for all users. This means legitimate users may experience slow responses or inability to use certain features while the server is under attack.

Mitigation Strategies

The immediate step to mitigate this vulnerability is to upgrade Discourse to one of the patched versions: 3.5.4, 2025.11.2, 2025.12.1, or 2026.1.0. No known workarounds are available.

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