CVE-2025-66488

Severity CVSS v4.0:

Pending analysis

Type:

Unavailable / Other

Publication date:

28/01/2026

Last modified:

28/01/2026

Description

Discourse is an open source discussion platform. A vulnerability present in versions prior to 3.5.4, 2025.11.2, 2025.12.1, and 2026.1.0 affects anyone who uses S3 for uploads. While scripts may be executed, they will only be run in the context of the S3/CDN domain, with no site credentials. Versions 3.5.4, 2025.11.2, 2025.12.1, and 2026.1.0 fix the issue. As a workaround, disallow html or xml files for uploads in authorized_extensions. For existing html xml uploads, site owners can consider deleting them.

Impact

Vector 3.x

CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:N/I:L/A:L CVSS v3.1 Severity and Metrics:

Base Score: 4.60 MEDIUM
Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:N/I:L/A:L

Attack Vector (AV): Network
Attack Complexity (AC): Low
Privileges Required (PR): Low
User Interaction (UI): Required
Scope (S): Unchanged
Confidentiality (C): None
Integrity (I): Low
Availability (A): Low

Base Score 3.x

4.60

Severity 3.x

MEDIUM

References to Advisories, Solutions, and Tools

https://github.com/discourse/discourse/security/advisories/GHSA-68jp-3934-62rx