CVE-2021-29453

Name: CVE-2021-29453
Creator: NVD / NIST
Published: 2021-04-19T19:15:17.717+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 6.5/10EPSS 1.00%

Last modified Jun 17, 2026

CVE-2021-29453 is a medium-severity vulnerability rated 6.5/10 on the CVSS scale. matrix-media-repo is an open-source multi-domain media repository for Matrix. Versions 1.2.6 and earlier of matrix-media-repo do not properly handle malicious images which are crafted to be small in file size, but large in complexity. EPSS estimates a 1.00% chance of exploitation in the next 30 days.

Description

matrix-media-repo is an open-source multi-domain media repository for Matrix. Versions 1.2.6 and earlier of matrix-media-repo do not properly handle malicious images which are crafted to be small in file size, but large in complexity. A malicious user could upload a relatively small image in terms of file size, using particular image formats, which expands to have extremely large dimensions during the process of thumbnailing. The server can be exhausted of memory in the process of trying to load the whole image into memory for thumbnailing, leading to denial of service. Version 1.2.7 has a fix for the vulnerability.

Metrics

CVSS 3.1

6.5/10

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

EPSS Probability

1.00%

58.4th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Vendor	Product	Versions
Matrix-Media-Repo Project	Matrix-Media-Repo	< 1.2.7

References

https://github.com/turt2live/matrix-media-repo/releases/tag/v1.2.7Release Notes, Third Party Advisory
https://github.com/turt2live/matrix-media-repo/security/advisories/GHSA-j889-h476-hh9hPatch, Third Party Advisory
https://hub.docker.com/r/turt2live/matrix-media-repo/tags?page=1&ordering=last_updatedThird Party Advisory
https://github.com/turt2live/matrix-media-repo/releases/tag/v1.2.7Release Notes, Third Party Advisory
https://github.com/turt2live/matrix-media-repo/security/advisories/GHSA-j889-h476-hh9hPatch, Third Party Advisory
https://hub.docker.com/r/turt2live/matrix-media-repo/tags?page=1&ordering=last_updatedThird Party Advisory

Timeline

Published: Apr 19, 2021
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-29453?

How severe is CVE-2021-29453?

CVE-2021-29453 has a CVSS score of 6.5/10 (MEDIUM severity). The EPSS model estimates a 1.00% probability of exploitation in the next 30 days.

How do I fix CVE-2021-29453?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2021-29453?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST