6.1

CVE-2025-66488

Discourse allows script execution in uploaded HTML/XML files on S3

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.
Daten sind bereitgestellt durch National Vulnerability Database (NVD)
Discourse ≫ Discourse SwEditionstable Version < 3.5.4
Discourse ≫ Discourse SwEditionstable Version >= 2025.11.0 < 2025.11.2
Discourse ≫ Discourse Version2025.12.0 SwEditionstable
Discourse ≫ Discourse Version2026.1.0 SwEditionstable
VulnDex Vulnerability Enrichment
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Zu dieser CVE wurde keine Warnung gefunden.
EPSS Metriken
Typ Quelle Score Percentile
EPSS FIRST.org 0.19% 0.086
CVSS Metriken
Quelle Base Score Exploit Score Impact Score Vector String
nvd@nist.gov 6.1 2.8 2.7
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
security-advisories@github.com 4.6 2.1 2.5
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:N/I:L/A:L
CWE-116 Improper Encoding or Escaping of Output

The product prepares a structured message for communication with another component, but encoding or escaping of the data is either missing or done incorrectly. As a result, the intended structure of the message is not preserved.

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