VULNERABILITY INTELLIGENCE

CVE-2025-66488

CVSS score4.6 MEDIUM
EPSS probability0.20%
CISA KEVNot currently listed
Published2026-01-28
Last modified2026-06-17
CVSS vectorCVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:N/I:L/A:L

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.

Weakness classification

  • security-advisories@github.com: CWE-116

Primary references