element-hq Vulnerabilities and Affected Products
Vulnerabilities associated with synapse.
Products
Clear product- synapse11 vulnerabilities
- element-web5 vulnerabilities
- element-android3 vulnerabilities
- element-x-android2 vulnerabilities
- element-call1 vulnerability
- element-desktop1 vulnerability
- element-x-ios1 vulnerability
- ess-helm1 vulnerability
- matrix-authentication-service1 vulnerability
- matrix-tools1 vulnerability
| Vulnerability | Title and context | CVSS | EPSS | PoCs | Signals | STIX action |
|---|---|---|---|---|---|---|
CVE-2026-45078MEDIUM | 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 in 1.152.1. | CVSS6.8v4.0 | EPSS0.128% | PoCs0 | SignalsNot listed in CISA KEVNo known ransomware useNo Nuclei templates | STIX |
CVE-2026-45076MEDIUM | Synapse pagination denial of serviceSynapse 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 to display room history. This vulnerability is fixed in 1.152.1. CWE-20May 28, 2026 | CVSS5.1v4.0 | EPSS0.369% | PoCs0 | SignalsNot listed in CISA KEVNo known ransomware useNo Nuclei templates | STIX |
CVE-2025-61672MEDIUM | Synapse: Invalid device keys degrade federation functionalitySynapse 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 outbound federation to other homeservers. The issue is patched in Synapse 1.138.3, 1.138.4, 1.139.1, and 1.139.2. Note that even though 1.138.3 and 1.139.1 fix the vulnerability, they inadvertently introduced an unrelated regression. For this… CWE-1287Oct 8, 2025 | CVSS5.3v4.0 | EPSS0.434% | PoCs0 | SignalsNot listed in CISA KEVNo known ransomware useNo Nuclei templates | STIX |
CVE-2025-30355HIGH | Synapse vulnerable to federation denial of service via malformed eventsSynapse 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 in Synapse v1.127.1. No known workarounds are available. CWE-20Mar 27, 2025 | CVSS7.1v3.1 | EPSS1.18% | PoCs0 | SignalsNot listed in CISA KEVNo known ransomware useNo Nuclei templates | STIX |
Synapse unauthenticated writes to the media repository allow planting of problematic contentSynapse 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 local homeserver in an unauthenticated way. The implication is that unauthenticated remote adversaries can use this functionality to plant problematic content into the media repository. Synapse 1.106 in… CWE-306Dec 3, 2024 | CVSS-v4.0 | EPSS0.419% | PoCs0 | SignalsNot listed in CISA KEVNo known ransomware useNo Nuclei templates | STIX | |
Synapse denial of service through media disk space consumptionSynapse 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 insufficient to mitigate this. This can lead to a denial of service, ranging from further media uploads/downloads failing to completely unavailability of the Synapse process, depending on how Synapse was deployed. Synapse 1.106 introduces a new … CWE-770Dec 3, 2024 | CVSS-v4.0 | EPSS0.572% | PoCs0 | SignalsNot listed in CISA KEVNo known ransomware useNo Nuclei templates | STIX | |
CVE-2024-52805HIGH | Synapse allows unsupported content types to lead to memory exhaustionSynapse 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 of service attacks. Synapse 1.120.1 resolves the issue by denying requests with unsupported multipart/form-data content type. CWE-770Dec 3, 2024 | CVSS8.2v4.0 | EPSS0.709% | PoCs0 | SignalsNot listed in CISA KEVNo known ransomware useNo Nuclei templates | STIX |
CVE-2024-52815HIGH | 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 functionality. Synapse 1.120.1 rejects such invalid invites received over federation and restores the ability to sync for affected users. CWE-20Dec 3, 2024 | CVSS8.7v4.0 | EPSS0.543% | PoCs0 | SignalsNot listed in CISA KEVNo known ransomware useNo Nuclei templates | STIX |
CVE-2024-53867MEDIUM | Synapse Matrix has a partial room state leak via Sliding SyncSynapse 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. CWE-497Dec 3, 2024 | CVSS4.3v3.1 | EPSS0.427% | PoCs0 | SignalsNot listed in CISA KEVNo known ransomware useNo Nuclei templates | STIX |
CVE-2024-53863HIGH | Synapse can be forced to thumbnail unexpected file formats, invoking external, potentially untrustworthy decodersSynapse 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 invoking external tools like Ghostscript for processing. This significantly expands the attack surface in a historically vulnerable area, presenting a risk that far outweighs the benefit, particularly since these formats are rarely used on the ope… CWE-434Dec 3, 2024 | CVSS8.2v4.0 | EPSS0.619% | PoCs0 | SignalsNot listed in CISA KEVNo known ransomware useNo Nuclei templates | STIX |
CVE-2024-31208MEDIUM | Synapse's V2 state resolution weakness allows DoS from remote room membersSynapse 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 high CPU consumption and accumulate excessive data in the database of such instances, resulting in a denial of service. Servers in private federations, or those that do not federate, are not affected. Server administrators should upgrade to 1.… CWE-770Apr 23, 2024 | CVSS6.5v3.1 | EPSS1.46% | PoCs0 | SignalsNot listed in CISA KEVNo known ransomware useNo Nuclei templates | STIX |