CVE-2026-46413 Discourse: Regular users can route multipart uploads into the admin backup store

What is CVE-2026-46413?

CVE-2026-46413 is a medium-severity missing authorization vulnerability in Discourse Discourse, published on 9 Jul 2026. Any signed-in user can exploit it over the network, with no action from the victim.

Official description

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.

Weakness: CWE-862

Which versions are affected by CVE-2026-46413?

1 open source package ship an affected version, including discourse. It affects 1 product.

Products include Discourse Discourse.

How do I fix CVE-2026-46413?

Upgrade discourse to a fixed version for your release line: 2026.1.5, 2026.4.2 or 2026.5.1.

Upgrade, and check permissions on every request on the server, not only in the interface. More about Missing authorization.

Is CVE-2026-46413 being exploited?

There is no known exploitation of CVE-2026-46413 in the wild and no public exploit code.

Other vulnerabilities in Discourse Discourse

• CVE-2021-41163 RCE via malicious SNS subscription payload Critical 10.0
• CVE-2022-36066 Discourse vulnerable to RCE via admins uploading maliciously zipped file Critical 9.1
• CVE-2022-39356 Discourse user account takeover via email and invite link High 8.9
• CVE-2023-22468 Discourse vulnerable to Cross-site Scripting in local oneboxes High 8.8
• CVE-2026-27934 Discourse leaks private topic title and post excerpt via user action API endpoint High 8.7

All Discourse Discourse vulnerabilities

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as BIT-discourse-2026-46413, GHSA-3mvf-q9rg-w6m7.