Is CVE-2024-53863 actively exploited?

No active exploitation of CVE-2024-53863 has been confirmed so far. Continue monitoring, as exploit status can change.

Can CVE-2024-53863 be exploited remotely?

Yes. CVE-2024-53863 is exploitable remotely over the network (CVSS attack vector: Network).

What is the CVSS score of CVE-2024-53863?

CVE-2024-53863 has a CVSS score of 9.1 (CRITICAL).

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CRITICAL

CVE-2024-53863

CWE-434Published: December 3, 2024· Updated: Jun 17, 2026

9.1

CVSS v3.1

Official Description

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.

NVD Source

Technical Analysis

CVE-2024-53863 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.

The vulnerability requires no privileges and no user interaction, making it a prime target for automated exploitation campaigns and worm-like propagation.

A successful exploit results in complete confidentiality breach (data exposure), full integrity compromise (data manipulation), with a CVSS base score of 9.1.