CVE-2026-45078

Synapse is an open source Matrix homeserver implementation. Prior to 1.152.1, local authenticated users can cause Synapse to starve other requests of CPU and lead to other requests failing, causing other users to be denied service. This vulnerability is fixed in 1.152.1...

Synapse Matrix has a partial room state leak via Sliding Sync

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...

PYSEC-2024-287

Synapse is an open-source Matrix homeserver. Synapse before version 1.106 allows, by design, unauthenticated remote participants to trigger a download and caching of remote media from a remote homeserver to the local media repository. Such content then also becomes available for download from the...

CVE-2024-53867 Synapse Matrix has a partial room state leak via Sliding Sync

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...

CVE-2023-42453

Synapse is an open-source Matrix homeserver written and maintained by the Matrix.org Foundation. Users were able to forge read receipts for any event if they knew the room ID and event ID. Note that the users were not able to view the events, but simply mark it as read. This could be confusing as...

DEBIAN-CVE-2023-32683

Synapse is a Matrix protocol homeserver written in Python with the Twisted framework. A discovered oEmbed or image URL can bypass the urlpreviewurlblacklist setting potentially allowing server side request forgery or bypassing network policies. Impact is limited to IP addresses allowed by the...

DEBIAN-CVE-2023-32682

Synapse is a Matrix protocol homeserver written in Python with the Twisted framework. In affected versions it may be possible for a deactivated user to login when using uncommon configurations. This only applies if any of the following are true: 1. JSON Web Tokens are enabled for login via the...

CVE-2023-32683

Synapse is a Matrix protocol homeserver written in Python with the Twisted framework. A discovered oEmbed or image URL can bypass the urlpreviewurlblacklist setting potentially allowing server side request forgery or bypassing network policies. Impact is limited to IP addresses allowed by the...

PYSEC-2023-85

Synapse is a Matrix protocol homeserver written in Python with the Twisted framework. A discovered oEmbed or image URL can bypass the urlpreviewurlblacklist setting potentially allowing server side request forgery or bypassing network policies. Impact is limited to IP addresses allowed by the...

CVE-2023-32323

Synapse is an open-source Matrix homeserver written and maintained by the Matrix.org Foundation. A malicious user on a Synapse homeserver X with permission to create certain state events can disable outbound federation from X to an arbitrary homeserver Y. Synapse instances with federation disable...

CVE-2021-21394

Synapse is a Matrix reference homeserver written in python pypi package matrix-synapse. Matrix is an ecosystem for open federated Instant Messaging and VoIP. In Synapse before version 1.28.0 Synapse is missing input validation of some parameters on the endpoints used to confirm third-party...