https://cve.radiocsirt.org/rss/recent/all/10 Most recent entries from all 2026-10-03T16:04:31.882394+00:00 Vulnerability-Lookup csirt@opendfir.org python-feedgen Contains only the most 10 recent entries. https://cve.radiocsirt.org/vuln/cve-2024-53867 CVE-2024-53867 — Synapse Matrix has a partial room state leak via Sliding Sync 2026-10-03T16:04:31.915561+00:00

Affected: element-hq synapse

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.

 https://cve.radiocsirt.org/vuln/ghsa-56w4-5538-8v8h GHSA-56w4-5538-8v8h — Synapse Matrix has a partial room state leak via Sliding Sync 2026-10-03T16:04:31.915620+00:00

Affected: PyPI: matrix-synapse

### 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](mailto:security@element.io).