CVE-2024-53863

Synapse is an open-source Matrix homeserver. In Synapse versions before 1.120.1, enabling the dynamic_thumbnails option or processing a specially crafted request could trigger the decoding and thumbnail generation of uncommon image formats, potentially invoking external tools like Ghostscript for processing. This significantly expands the attack surface in a historically vulnerable area, presenting a risk that far outweighs the benefit, particularly since these formats are rarely used on the open web or within the Matrix ecosystem. Synapse 1.120.1 addresses the issue by restricting thumbnail generation to images in the following widely used formats: PNG, JPEG, GIF, and WebP. This vulnerability is fixed in 1.120.1.

CVSS v3 9.1 CRITICAL

9.1^/10

CVSS v3 : CRITICAL

Vector :

Exploitability : 3.9 / Impact : 5.2

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction NONE

Confidentiality Impact HIGH

Integrity Impact HIGH

Availability Impact NONE

Scope UNCHANGED

References

Link	Resource
https://github.com/element-hq/synapse/security/advisories/GHSA-vp6v-whfm-rv3g	Vendor Advisory

Configurations

Configuration 1 (hide)

cpe:2.3:a:matrix:synapse:*:*:*:*:*:*:*:*

History

26 Aug 2025, 14:59

Type	Values Removed	Values Added
First Time		Matrix Matrix synapse
CVSS	v2 : ~~unknown~~ v3 : ~~unknown~~	v2 : unknown v3 : 9.1
References	~~() https://github.com/element-hq/synapse/security/advisories/GHSA-vp6v-whfm-rv3g -~~	() https://github.com/element-hq/synapse/security/advisories/GHSA-vp6v-whfm-rv3g - Vendor Advisory
CPE		cpe:2.3:a:matrix:synapse::::::::

03 Dec 2024, 17:15

Type	Values Removed	Values Added
New CVE

Information

Published : 2024-12-03 17:15

Updated : 2025-08-26 14:59

NVD link : CVE-2024-53863

Mitre link : CVE-2024-53863

CVE.ORG link : CVE-2024-53863

JSON object : View

Products Affected

matrix

synapse

CWE

CWE-434

Unrestricted Upload of File with Dangerous Type

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