Discourse has DoS vulnerability in username change endpoint (CVE-2025-68659)

Summary

Discourse has DoS vulnerability in username change endpoint

Original description

The description as published by the source.

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.

Source: OSV.dev (Open Source Vulnerabilities) NVD GitHub Advisory OSV

Affected packages

Bitnami discourse

[{"type":"SEMVER","events":[{"introduced":"0"},{"fixed":"3.5.4"},{"introduced":"2025.11.0"},{"fixed":"2025.11.2"},{"introduced":"2025.12.0"},{"fixed":"2025.12.1"},{"introduced":"2026.1.0"},{"fixed":"2026.1.0"}]}]

References

advisory github.com
web nvd.nist.gov