PYSEC-2026-1610
See a problem?- Import Source
- https://github.com/pypa/advisory-database/blob/main/vulns/matrix-synapse/PYSEC-2026-1610.yaml
- JSON Data
- https://api.osv.dev/v1/vulns/PYSEC-2026-1610
- Aliases
- Published
- 2026-07-07T14:34:46Z
- Modified
- 2026-07-07T17:47:03Z
- Severity
-
- 4.3 (Medium) CVSS_V3 - CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N CVSS Calculator
- Summary
- Synapse Matrix has a partial room state leak via Sliding Sync
- Details
-
Impact
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.
Patches
Synapse version 1.120.1 fixes the problem.
Workarounds
Disable Sliding Sync.
References
https://github.com/matrix-org/matrix-spec-proposals/pull/4186 https://github.com/element-hq/synapse/blob/d80cd57c54427687afcb48740d99219c88a0fff1/synapse/config/experimental.py#L341-L344
For more information
If you have any questions or comments about this advisory, please email us at security at element.io.
- References
-
- https://github.com/element-hq/synapse/security/advisories/GHSA-56w4-5538-8v8h
- https://nvd.nist.gov/vuln/detail/CVE-2024-53867
- https://github.com/matrix-org/matrix-spec-proposals/pull/4186
- https://github.com/element-hq/synapse
- https://pypi.org/project/matrix-synapse
- https://github.com/advisories/GHSA-56w4-5538-8v8h
Affected packages
PyPI / matrix-synapse
Package
- Name
- matrix-synapse
- View open source insights on deps.dev
- Purl
- pkg:pypi/matrix-synapse