Input Validation Flaw in Discourse Discussion Platform
CVE-2026-46413

6.5MEDIUM

Key Information:

Vendor

Discourse
Status
Discourse
Vendor
CVE Published:
9 July 2026

What is CVE-2026-46413?

Discourse, an open-source discussion platform, exhibits an input validation flaw that allows unauthorized users to route direct S3 multipart uploads through the ExternalUploadManager into the admin backup storage. This vulnerability has been addressed in versions 2026.6.0, 2026.5.1, 2026.4.2, and 2026.1.5, ensuring improved security measures to prevent potential exploits.

Affected Version(s)

discourse >= 2026.1.0-latest, < 2026.1.5 < 2026.1.0-latest, 2026.1.5

discourse >= 2026.4.0-latest, < 2026.4.2 < 2026.4.0-latest, 2026.4.2

discourse >= 2026.5.0-latest, < 2026.5.1 < 2026.5.0-latest, 2026.5.1

References

https://github.com/discourse/discourse/security/advisorie...
x_refsource_CONFIRM
https://github.com/discourse/discourse/commit/1f1ded8dd36...
x_refsource_MISC
https://github.com/discourse/discourse/commit/7ddde266617...
x_refsource_MISC

CVSS V3.1

Score:
6.5
Severity:
MEDIUM
Confidentiality:
None
Integrity:
High
Availability:
None
Attack Vector:
Network
Attack Complexity:
Low
Privileges Required:
Low
User Interaction:
None
Scope:
Unchanged

Timeline

  • Vulnerability published

  • Vulnerability Reserved

.