Incorrect authorization in Discourse - #VU165860
Published: November 11, 2026
Vulnerability identifier: #VU165860
CSH Severity: Low
CVSS v4: 7.2 [CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:H/VA:L/SC:N/SI:N/SA:N]
CVE-ID: N/A
CWE-ID: CWE-863
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote user to take over accessible user accounts and potentially gain full administrator access.
The vulnerability exists due to improper authorization in Discourse user-update and user-creation endpoints when processing external_ids from administrator-authenticated scoped API keys. A remote user can use a scoped key and applicable external login provider to bind a target account to a controlled identity through users:update, enabling account takeover, or reassign an existing managed-provider association through users:create, compromising that association.
Affected software
Discourse
Remediation
Install security update from vendor's website.
Discourse - addressed in versions 2026.7.5, 2026.9.2, 2026.10.1