synapse at a glance
- Last 12 months
- 2
- Critical · all time
- 0
- Exploited · all time
- 0
- Public exploit · all time
- 0
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| Month | Vulnerabilities | Critical |
|---|---|---|
| Nov 2026 | 0 | 0 |
| Oct 2026 | 0 | 0 |
| Sep 2026 | 0 | 0 |
| Aug 2026 | 0 | 0 |
| Jul 2026 | 0 | 0 |
| Jun 2026 | 0 | 0 |
| May 2026 | 2 | 0 |
| Apr 2026 | 0 | 0 |
| Mar 2026 | 0 | 0 |
| Feb 2026 | 0 | 0 |
| Jan 2026 | 0 | 0 |
| Dec 2025 | 0 | 0 |
| Nov 2025 | 0 | 0 |
| Oct 2025 | 1 | 0 |
| Sep 2025 | 0 | 0 |
| Aug 2025 | 0 | 0 |
| Jul 2025 | 0 | 0 |
| Jun 2025 | 0 | 0 |
| May 2025 | 0 | 0 |
| Apr 2025 | 0 | 0 |
| Mar 2025 | 1 | 0 |
| Feb 2025 | 0 | 0 |
| Jan 2025 | 0 | 0 |
| Dec 2024 | 6 | 0 |
11 results · Feed
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Medium 6.8
Synapse CPU starvation (Denial of Service)
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…
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Medium 5.1
Synapse pagination denial of service
Synapse is an open source Matrix homeserver implementation. Prior to 1.152.1, in federated rooms, malicious homeservers can craft room events in such a way that prevents Synapse from providing full history to paginating clients. Clients could therefore fail t…
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Medium 5.3
Synapse: Invalid device keys degrade federation functionality
Synapse is an open source Matrix homeserver implementation. Lack of validation for device keys in Synapse before 1.138.3 and in Synapse 1.139.0 allow an attacker registered on the victim homeserver to degrade federation functionality, unpredictably breaking o…
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High 7.1
Synapse vulnerable to federation denial of service via malformed events
Synapse is an open source Matrix homeserver implementation. A malicious server can craft events which, when received, prevent Synapse version up to 1.127.0 from federating with other servers. The vulnerability has been exploited in the wild and has been fixed…
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Medium 5.3
Synapse unauthenticated writes to the media repository allow planting of problematic content
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 b…
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High 7.5
Synapse denial of service through media disk space consumption
Synapse is an open-source Matrix homeserver. Synapse versions before 1.106 are vulnerable to a disk fill attack, where an unauthenticated adversary can induce Synapse to download and cache large amounts of remote media. The default rate limit strategy is insu…
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High 8.2
Synapse allows unsupported content types to lead to memory exhaustion
Synapse is an open-source Matrix homeserver. In Synapse before 1.120.1, multipart/form-data requests can in certain configurations transiently increase memory consumption beyond expected levels while processing the request, which can be used to amplify denial…
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High 8.7
Synapse allows a a malformed invite to break the invitee's `/sync`
Synapse is an open-source Matrix homeserver. Synapse versions before 1.120.1 fail to properly validate invites received over federation. This vulnerability allows a malicious server to send a specially crafted invite that disrupts the invited user's /sync fun…
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Medium 4.3
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 f…
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High 8.2
Synapse can be forced to thumbnail unexpected file formats, invoking external, potentially untrustworthy decoders
Synapse is an open-source Matrix homeserver. In Synapse versions before 1.120.1, enabling the dynamic_thumbnails option or processing a specially crafted request could trigger the decoding and thumbnail generation of uncommon image formats, potentially invoki…
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Medium 6.5
Synapse's V2 state resolution weakness allows DoS from remote room members
Synapse is an open-source Matrix homeserver. A remote Matrix user with malicious intent, sharing a room with Synapse instances before 1.105.1, can dispatch specially crafted events to exploit a weakness in the V2 state resolution algorithm. This can induce hi…