NVD / CVE Program· CNA GitHub_M

CVE-2024-56515: Untrusted file formats can be thumbnailed, invoking potentially further untrusted decoders in Matrix Media Repo

Noroxi assessment

Priority: Monitor (action score 26/100)

The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
Probability of exploitation in the next 30 days: 0.65% (FIRST EPSS); higher than 51% of all records.
Anyone who can reach it over the internet can trigger it. A low-privileged account is enough. No user action is required. No special conditions are required; it is repeatable.
Fixed version: github.com/t2bot/matrix-media-repo (Go) 1.3.8; govulncheck-vulndb (openSUSE:Leap 15.6) 0.0.20250128T150132-150000.1.29.1; govulncheck-vulndb (openSUSE:Tumbleweed) 0.0.20250117T214834-1.1.

Low priority for now. Upgrade to github.com/t2bot/matrix-media-repo (Go) 1.3.8; govulncheck-vulndb (openSUSE:Leap 15.6) 0.0.20250128T150132-150000.1.29.1; govulncheck-vulndb (openSUSE:Tumbleweed) 0.0.20250117T214834-1.1 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

Matrix Media Repo (MMR) is a highly configurable multi-homeserver media repository for Matrix. If SVG or JPEGXL thumbnailers are enabled (they are disabled by default), a user may upload a file which claims to be either of these types and request a thumbnail to invoke a different decoder in ImageMagick. In some ImageMagick installations, this includes the capability to run Ghostscript to decode the image/file. If MP4 thumbnailers are enabled (also disabled by default), the same issue as above may occur with the ffmpeg installation instead. MMR uses a number of other decoders for all other file types when preparing thumbnails. Theoretical issues are possible with these decoders, however in testing they were not possible to exploit. This is fixed in MMR v1.3.8. MMR now inspects the mimetype of media prior to thumbnailing, and picks a thumbnailer based on those results instead of relying on user-supplied values. This may lead to fewer thumbnails when obscure file shapes are used. This also helps narrow scope of theoretical issues with all decoders MMR uses for thumbnails. Users are advised to upgrade. Users unable to upgrade may disable the SVG, JPEGXL, and MP4 thumbnail types in the MMR config which prevents the decoders from being invoked. Further disabling uncommon file types on the server is recommended to limit risk surface. Containers and other similar technologies may also be used to limit the impact of vulnerabilities in external decoders, like ImageMagick and ffmpeg. Some installations of ImageMagick may disable "unsafe" file types, like PDFs, already. This option can be replicated to other environments as needed. ffmpeg may be compiled with limited decoders/codecs. The Docker image for MMR disables PDFs and similar formats by default.

MediumCVSS 6.5 · v3.1—No exploit Fix available

Deserialization

Published: Jan 16, 2025
Updated: Jun 17, 2026
EPSS: 0.6% · 51th percentile
CWE: CWE-502

Report tools

JSON

Action score

Monitor

Low priority for now.

CVSS: 26 / 40 · 6.5 / 10
CISA KEV: 0 / 30 · Not listed
EPSS: 0 / 30 · 0.6%

CISA SSVC decision

Exploitation: none
Automatable: no
Technical impact: partial

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD: 6.5
CNA · GitHub_M: 6.8; 0.3 point gap

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

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

Get told when this record changes

Not in KEV: no record of exploitation in the wild
No public exploit code on record
A fix has been released

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

Vendor	Product	CPE
t2bot	matrix-media-repo	cpe:2.3:a:t2bot:matrix-media-repo

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

t2bot matrix-media-repobefore 1.3.8

Versions reported by the vendor

Affected version ranges reported by the assigning authority (GitHub_M). Independent of NVD's CPE analysis and usually ahead of it.

t2bot matrix-media-repo
- < 1.3.8affected

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

Ecosystem	Package	Affected range	Fix
Go	github.com/t2bot/matrix-media-repo	before 1.3.8	1.3.8
openSUSE:Leap 15.6	govulncheck-vulndb	before 0.0.20250128T150132-150000.1.29.1	0.0.20250128T150132-150000.1.29.1
openSUSE:Tumbleweed	govulncheck-vulndb	before 0.0.20250117T214834-1.1	0.0.20250117T214834-1.1
SUSE:Linux Enterprise Module for Package Hub 15 SP6	govulncheck-vulndb	before 0.0.20250128T150132-150000.1.29.1	0.0.20250128T150132-150000.1.29.1

Same product

t2bot: all records

Other highest-scoring records for the same primary product.

CVE-2024-52791Denial of service through memory exhaustion in Matrix Media Repo
30Monitor
CVE-2024-36403Denial of service/high operating costs through unauthenticated downloads in Matrix Media Repo
30Monitor
CVE-2024-52602Server-Side Request Forgery (SSRF) on redirects and federation in Matrix Media Repo
21Monitor

Published before and after this one in the same product

← EarlierCVE-2024-36402Jan 16, 2025 · Unauthenticated writes to the media repository allow planting of problematic content in Matrix Media Repo
21Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / package	Fixed version	Source
Go:github.com/t2bot/matrix-media-repo	1.3.8	Package registry (OSV)
opensuse:govulncheck-vulndb	0.0.20250128T150132-150000.1.29.1 · openSUSE:Leap 15.6	Package registry (OSV)
suse:govulncheck-vulndb	0.0.20250128T150132-150000.1.29.1 · SUSE:Linux Enterprise Module for Package Hub 15 SP6	Package registry (OSV)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

No history yet (it accumulates with the daily EPSS job).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

—

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

CVE-2024-364020 days apartUnauthenticated writes to the media repository allow planting of problematic content in Matrix Media Repo
21Monitor

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

Technical details

Attack conditions

Anyone who can reach it over the internet can trigger it.
A low-privileged account is enough.
No user action is required.
No special conditions are required; it is repeatable.

If successful

Confidentiality: high · data can be read
Integrity: none
Availability: none

Attack vector: Network
Attack complexity: Low
Privileges required: Low
User interaction: None
Scope: Unchanged
Confidentiality impact: High
Integrity impact: None
Availability impact: None

Weakness class (CWE)

CWE-502 · Deserialization of Untrusted Data

CVSS vector

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

nvd-primary

Root cause

Data received over the network is deserialized into the language’s native object format without verifying its source. Code paths inside the object can be triggered during deserialization.

The bug in code

The whole CWE-502 class

A representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.

Vulnerable

python

1payload = sock.recv(65536)
2job = pickle.loads(payload)

Fixed

python

1payload = sock.recv(65536)
2if not hmac.compare_digest(sign(payload), header_sig):
3    raise PermissionError("invalid signature")
4job = JobSchema.validate(json.loads(payload))