matrix-media-repo (MMR) allows unauthenticated writes to the media repository, which may allow planting of problematic content

Exploitation

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

CVSS

5.3 · CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

EPSS

• CVE-2024-36402: 0.56% estimated exploitation activity in the next 30 days; percentile 46.94 (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 MMR before version 1.3.5 allows, by design, unauthenticated remote participants to trigger a download and caching of remote media from a remote homeserver to the local media repository. Such content then also becomes available for download from the local homeserver in an unauthenticated way. The implication is that unauthenticated remote adversaries can use this functionality to plant problematic content into the media repository. Patches MMR 1.3.5 introduces a partial mitigation in the form of new endpoints which require authentication for media downloads. The unauthenticated endpoints will be frozen in a future release, closing the attack vector. Workarounds Though extremely limited, server operators can use more strict rate limits based on IP address. References https://github.com/matrix-org/matrix-spec-proposals/pull/3916

Published by the source

16 Jan 2025, 19:05 UTC

Last modified by the source

20 Aug 2025, 19:13 UTC

Source last checked

26 Oct 2026, 15:10 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-8vmr-h7h5-cqhg

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# Patch Next advisory brief: CVE-2024-36402

Advisory: matrix-media-repo (MMR) allows unauthenticated writes to the media repository, which may allow planting of problematic content
IDs: CVE-2024-36402, GHSA-8vmr-h7h5-cqhg
Record: https://patchnext.com/advisories/cve-2024-36402 (revision 1, source checked 26 Oct 2026, 15:10 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 5.3)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: github.com/t2bot/matrix-media-repo 1.3.5. A vendor fix does not mean a deployment is fixed.

## Affected components
- Go github.com/t2bot/matrix-media-repo: affected < 1.3.5; fixed in 1.3.5

## Suggested inspection (read-only)
- Go github.com/t2bot/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/t2bot/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-8vmr-h7h5-cqhg (GitHub-reviewed advisory GHSA-8vmr-h7h5-cqhg lists affected ranges: Go github.com/t2bot/matrix-media-repo >=0 <1.3.5)

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