Exposure of Sensitive System Information to an Unauthorized Control Sphere in Synapse - CVE-2024-53867
Published: December 3, 2024 / Updated: April 23, 2026
Vulnerability identifier: #VU127003
CSH Severity: Low
CVSS v4.0: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:U/U:Clear
CVE-ID: CVE-2024-53867
CWE-ID: CWE-497
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vendor: Matrix.org
Affected software:
Synapse
Synapse
Detailed vulnerability description
The vulnerability allows a remote user to disclose sensitive information.
The vulnerability exists due to exposure of sensitive information in the Sliding Sync feature when handling synchronization requests for users no longer in a room. A remote user can request synchronization data to disclose sensitive information.
Only partial room state changes are exposed; non-state events such as messages are not affected.
How to mitigate CVE-2024-53867
Install security update from vendor's website.