matrix-media-repo (MMR) allows denial of service/high operating costs through unauthenticated downloads

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-2024-36403: 0.71% estimated exploitation activity in the next 30 days; percentile 53.59 (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 is vulnerable to unbounded disk consumption, where an unauthenticated adversary can induce it to download and cache large amounts of remote media files. MMR's typical operating environment uses S3-like storage as a backend, with file-backed store as an alternative option. Instances using a file-backed store or those which self-host an S3 storage system are therefore vulnerable to a disk fill attack. Once the disk is full, authenticated users will be unable to upload new media, resulting in denial of service. For instances configured to use a cloud-based S3 storage option, this could result in high service fees instead of a denial of service. Patches MMR 1.3.5 introduces a new default-on "leaky bucket" rate limit to reduce the amount of data a user can request at a time. This does not fully address the issue, but does limit an unauthenticated user's ability to request large amounts of data. Operators should note that the leaky bucket implementation…

Published by the source

16 Jan 2025, 19:05 UTC

Last modified by the source

17 Jan 2025, 15:39 UTC

Source last checked

26 Oct 2026, 15:08 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-vc2m-hw89-qjxf

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# Patch Next advisory brief: CVE-2024-36403

Advisory: matrix-media-repo (MMR) allows denial of service/high operating costs through unauthenticated downloads
IDs: CVE-2024-36403, GHSA-vc2m-hw89-qjxf
Record: https://patchnext.com/advisories/cve-2024-36403 (revision 1, source checked 26 Oct 2026, 15:08 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-vc2m-hw89-qjxf (GitHub-reviewed advisory GHSA-vc2m-hw89-qjxf lists affected ranges: Go github.com/t2bot/matrix-media-repo >=0 <1.3.5)

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