matrix-media-repo: Unsafe media served inline on download endpoints

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

4.1 · CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:N/A:N

EPSS

• CVE-2023-41318: 0.52% estimated exploitation activity in the next 30 days; percentile 44.01 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Impact A malicious user can upload an SVG image containing JavaScript to their server. When matrix-media-repo is asked to serve that media via the /matrix/media/(r0|v3)/download endpoint, it would be served with a Content-Disposition of inline. This can allow JavaScript to run in the browser if a client links to the /download endpoint directly. Server operators which do not share a domain between matrix-media-repo and other services are not affected, but are encouraged to upgrade regardless. Patches https://github.com/turt2live/matrix-media-repo/commit/77ec2354e8f46d5ef149d1dcaf25f51c04149137 and https://github.com/turt2live/matrix-media-repo/commit/bf8abdd7a5371118e280c65a8e0ec2b2e9bdaf59 fix the issue. Operators should upgrade to v1.3.0 as soon as possible. Workarounds The Content-Disposition header can be overridden by the reverse proxy in front of matrix-media-repo to always use attachment, defeating this issue at the cost of "worse" user experience when clicking download links.…

Published by the source

8 Sep 2023, 13:18 UTC

Last modified by the source

10 Nov 2023, 05:04 UTC

Source last checked

26 Oct 2026, 15:00 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-5crw-6j7v-xc72

Preview the exact text before you copy it. Commands are read-only suggestions; review them before running anything.

# Patch Next advisory brief: CVE-2023-41318

Advisory: matrix-media-repo: Unsafe media served inline on download endpoints
IDs: CVE-2023-41318, GHSA-5crw-6j7v-xc72
Record: https://patchnext.com/advisories/cve-2023-41318 (revision 1, source checked 26 Oct 2026, 15:00 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 4.1)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: github.com/turt2live/matrix-media-repo 1.3.0. A vendor fix does not mean a deployment is fixed.

## Affected components
- Go github.com/turt2live/matrix-media-repo: affected < 1.3.0; fixed in 1.3.0

## Suggested inspection (read-only)
- Go github.com/turt2live/matrix-media-repo: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on github.com/turt2live/matrix-media-repo.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-5crw-6j7v-xc72 (GitHub-reviewed advisory GHSA-5crw-6j7v-xc72 lists affected ranges: Go github.com/turt2live/matrix-media-repo >=0 <1.3.0)

Commands are suggestions: review each one before running it.