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 in Synapse v1.127.1....
Product
matrix synapse vulnerabilities
40 published CVES affecting matrix synapse, from public sources (CVE.org, NVD, CISA KEV, FIRST EPSS, OSV).
- Total
- 40
- Critical
- 1
- High
- 15
- Medium
- 21
- Low
- 3
- Unscored
- 0
- CISA KEV
- 0
Latest matrix synapse CVEs
Newest publication first · page 1 of 2
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HighCVSS 7.5 EPSS 1.2%
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MediumCVSS 5.3 EPSS 0.43%
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...
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HighCVSS 7.5 EPSS 0.60%
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 insufficient to mitigate...
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HighCVSS 8.2 EPSS 0.74%
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 of service attacks....
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HighCVSS 8.7 EPSS 0.57%
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...
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HighCVSS 8.2 EPSS 0.61%
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 invoking external tools lik...
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MediumCVSS 6.5 EPSS 1.5%
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 high CPU consumption an...
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MediumCVSS 5.3 EPSS 1.2%
Synapse is an open-source Matrix homeserver Prior to versions 1.95.1 and 1.96.0rc1, cached device information of remote users can be queried from Synapse. This can be used to enumerate the remote users known to a homeserver. System administrators are encouraged to upgrade to Syna...
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CVE-2023-45129 matrix-synapse vulnerable to denial of service due to malicious server ACL events
PublishedMediumCVSS 4.9 EPSS 1.4%Synapse is an open-source Matrix homeserver written and maintained by the Matrix.org Foundation. Prior to version 1.94.0, a malicious server ACL event can impact performance temporarily or permanently leading to a persistent denial of service. Homeservers running on a closed fede...
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CVE-2023-41335 Temporary storage of plaintext passwords during password changes in matrix synapse
PublishedLowCVSS 3.7 EPSS 0.39%Synapse is an open-source Matrix homeserver written and maintained by the Matrix.org Foundation. When users update their passwords, the new credentials may be briefly held in the server database. While this doesn't grant the server any added capabilities—it already learns the use...
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CVE-2023-42453 Improper validation of receipts allows forged read receipts in matrix synapse
PublishedMediumCVSS 4.3 EPSS 0.78%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 co...
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CVE-2023-32683 URL deny list bypass via oEmbed and image URLs when generating previews in Synapse
PublishedMediumCVSS 5.4 EPSS 0.61%Synapse is a Matrix protocol homeserver written in Python with the Twisted framework. A discovered oEmbed or image URL can bypass the url_preview_url_blacklist setting potentially allowing server side request forgery or bypassing network policies. Impact is limited to IP addresse...
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MediumCVSS 5.4 EPSS 0.75%
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...
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MediumCVSS 6.5 EPSS 0.94%
Synapse is an open-source Matrix homeserver written and maintained by the Matrix.org Foundation. If Synapse and a malicious homeserver are both joined to the same room, the malicious homeserver can trick Synapse into accepting previously rejected events into its view of the curre...
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MediumCVSS 5.0 EPSS 0.64%
Synapse is an open-source Matrix homeserver written and maintained by the Matrix.org Foundation. The Matrix Federation API allows remote homeservers to request the authorization events in a room. This is necessary so that a homeserver receiving some events can validate that those...
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MediumCVSS 4.3 EPSS 0.98%
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 f...
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MediumCVSS 5.3 EPSS 0.94%
Synapse before 1.52.0 with URL preview functionality enabled will attempt to generate URL previews for media stream URLs without properly limiting connection time. Connections will only be terminated after max_spider_size (default: 10M) bytes have been downloaded, which can in so...
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HighCVSS 7.5 EPSS 1.2%
Synapse is an open-source Matrix homeserver written and maintained by the Matrix.org Foundation. The Matrix specification specifies a list of event authorization rules which must be checked when determining if an event should be accepted into a room. In versions of Synapse up to...
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MediumCVSS 6.5 EPSS 1.7%
Synapse is an open source home server implementation for the Matrix chat network. In versions prior to 1.61.1 URL previews of some web pages can exhaust the available stack space for the Synapse process due to unbounded recursion. This is sometimes recoverable and leads to an err...
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HighCVSS 7.5 EPSS 1.6%
Synapse is a package for Matrix homeservers written in Python 3/Twisted. Prior to version 1.47.1, Synapse instances with the media repository enabled can be tricked into downloading a file from a remote server into an arbitrary directory. No authentication is required for the aff...
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CVE-2021-39164 Improper authorisation of /members discloses room membership to non-members
PublishedLowCVSS 3.1 EPSS 1.5%Matrix is an ecosystem for open federated Instant Messaging and Voice over IP. In versions 1.41.0 and prior, unauthorised users can access the membership (list of members, with their display names) of a room if they know the ID of the room. The vulnerability is limited to rooms w...
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LowCVSS 3.1 EPSS 0.90%
Matrix is an ecosystem for open federated Instant Messaging and Voice over IP. In versions 1.41.0 and prior, unauthorised users can access the name, avatar, topic and number of members of a room if they know the ID of the room. This vulnerability is limited to homeservers where t...
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MediumCVSS 5.3 EPSS 1.6%
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 1.33.2 "Push rules" can specify conditions under which they will match, including event_match,...
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MediumCVSS 6.3 EPSS 0.94%
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 requests to user provided domains were not restricted to external IP addresses when tra...
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MediumCVSS 6.5 EPSS 1.6%
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...
Sources: CVE.org, NVD, CISA KEV, FIRST EPSS, OSV and public exploit-reference metadata. Product matching comes from the published CVE records. A proof-of-concept means public code exists; it is not evidence of exploitation.