Auth bypass in Discourse
CVE-2026-46413
Discourse is an open-source discussion platform. Prior to 2026.6.0, 2026.5.1, 2026.4.2, and 2026.1.5, regular users could route direct S3 multipart uploads through ExternalUploadManager into the admin backup store. This issue is fixed in versions 2026.6.0, 2026.5.1, 2026.4.2, and 2026.1.5.
Vulnerability class: Broken Access Control
Published · last modified .
CVSS v3 metric
CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N.
EPSS exploit prediction
EPSS: 0.005 (41.9th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 42nd percentile — 41.9% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.005 · newest: 0.005 · change: 0.000
Affected products
- Discourse — versions >= 2026.5.0-latest, < 2026.5.1, >= 2026.4.0-latest, < 2026.4.2, 2026.6.0
Weakness classification (CWE)
References
- github.com/discourse/discourse/commit/1f1ded8dd361d81786bff17b35e1138d6ee299c0 (Patch)
- github.com/discourse/discourse/commit/7ddde266617b452152c1bf5f903f6c07be38fc40 (Patch)
- github.com/discourse/discourse/commit/a53df26dcf7e50ce2b20bfd5454a0c9d44b8fc7d (Patch)
- github.com/discourse/discourse/commit/abaa664c5df84026efb2ca264ba0f5586c3f2b01 (Patch)
- github.com/discourse/discourse/releases/tag/v2026.1.5 (Release Notes)
- github.com/discourse/discourse/releases/tag/v2026.4.2 (Release Notes)
- github.com/discourse/discourse/releases/tag/v2026.5.1 (Release Notes)
- github.com/discourse/discourse/releases/tag/v2026.6.0 (Release Notes)
- github.com/discourse/discourse/security/advisories/GHSA-3mvf-q9rg-w6m7 (Mitigation, Vendor Advisory)
Frequently asked questions
- What is CVE-2026-46413?
- CVE-2026-46413 is a medium-severity vulnerability in Discourse, classified under Missing Authorization. CVSS score: 6.5/10. Published 2026-07-09.
- How severe is CVE-2026-46413?
- Medium severity. CVSS v3 base score is 6.5 out of 10.