Is CVE-2024-37303 actively exploited?

No active exploitation of CVE-2024-37303 has been confirmed so far. Continue monitoring, as exploit status can change.

Can CVE-2024-37303 be exploited remotely?

Yes. CVE-2024-37303 is exploitable remotely over the network (CVSS attack vector: Network).

What is the CVSS score of CVE-2024-37303?

CVE-2024-37303 has a CVSS score of 5.3 (MEDIUM).

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MEDIUM

CVE-2024-37303

CWE-306Published: December 3, 2024· Updated: Jun 17, 2026

5.3

CVSS v3.1

Official Description

Synapse is an open-source Matrix homeserver. Synapse before version 1.106 allows, by design, unauthenticated remote participants to trigger a download and caching of remote media from a remote homeserver to the local media repository. Such content then also becomes available for download from the local homeserver in an unauthenticated way. The implication is that unauthenticated remote adversaries can use this functionality to plant problematic content into the media repository. Synapse 1.106 introduces a partial mitigation in the form of new endpoints which require authentication for media downloads. The unauthenticated endpoints will be frozen in a future release, closing the attack vector.

NVD Source

Technical Analysis

CVE-2024-37303 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.