Interpretation Conflict in Synapse - CVE-2024-53863
Published: December 3, 2024 / Updated: April 23, 2026
Vulnerability identifier: #VU127000
CSH Severity: Medium
CVSS v4: 6.9 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N]
CVE-ID: CVE-2024-53863
CWE-ID: CWE-436
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to invoke potentially untrustworthy decoders.
The vulnerability exists due to improper restriction of processed file formats in thumbnail generation when processing a specially crafted request. A remote attacker can send a specially crafted request to invoke potentially untrustworthy decoders.
Instances with the dynamic_thumbnails option enabled are affected.
Affected software
Synapse
Fedora
matrix-synapse
Fedora
matrix-synapse
How to mitigate CVE-2024-53863
Install security update from vendor's website.
Synapse - update to 1.120.1
matrix-synapse - addressed in versions 1.111.1-3.fc40, 1.118.0-3.fc41
matrix-synapse - addressed in versions 1.111.1-3.fc40, 1.118.0-3.fc41