Description
Synapse is an open-source Matrix homeserver. The Sliding Sync feature on Synapse versions between 1.113.0rc1 and 1.120.0 can leak partial room state changes to users no longer in a room. Non-state events, like messages, are unaffected. This vulnerability is fixed in 1.120.1.
Published: 2024-12-03
Score: 4.3 Medium
EPSS: < 1% Very Low
KEV: No
Impact: n/a
Action: n/a
AI Analysis

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Remediation

No vendor fix or workaround currently provided.

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Tracking

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Advisories
Source ID Title
EUVD EUVD EUVD-2024-3430 Synapse is an open-source Matrix homeserver. The Sliding Sync feature on Synapse versions between 1.113.0rc1 and 1.120.0 can leak partial room state changes to users no longer in a room. Non-state events, like messages, are unaffected. This vulnerability is fixed in 1.120.1.
Github GHSA Github GHSA GHSA-56w4-5538-8v8h Synapse Matrix has a partial room state leak via Sliding Sync
History

Wed, 16 Jul 2025 13:45:00 +0000

Type Values Removed Values Added
Metrics epss

{'score': 0.00022}

epss

{'score': 0.00018}


Tue, 03 Dec 2024 19:15:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Tue, 03 Dec 2024 17:00:00 +0000

Type Values Removed Values Added
Description Synapse is an open-source Matrix homeserver. The Sliding Sync feature on Synapse versions between 1.113.0rc1 and 1.120.0 can leak partial room state changes to users no longer in a room. Non-state events, like messages, are unaffected. This vulnerability is fixed in 1.120.1.
Title Synapse Matrix has a partial room state leak via Sliding Sync
Weaknesses CWE-497
References
Metrics cvssV3_1

{'score': 4.3, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N'}


Subscriptions

Element-hq Synapse
cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published:

Updated: 2024-12-03T19:07:19.919Z

Reserved: 2024-11-22T17:30:02.145Z

Link: CVE-2024-53867

cve-icon Vulnrichment

Updated: 2024-12-03T19:07:15.657Z

cve-icon NVD

Status : Deferred

Published: 2024-12-03T17:15:12.787

Modified: 2026-04-15T00:35:42.020

Link: CVE-2024-53867

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2025-07-12T22:44:38Z

Weaknesses