MediumFix available
matrix-synapse, synapse — security advisory
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 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 1.105.1 or later. Some workarounds are available. One can ban the malicious users or ACL block servers from the rooms and/or leave the room and purge the room using the admin API.
- Products
- matrix-synapse, synapse
- Affected versions
- 0.19.2+dfsg-6, 0.2.99.1-1, 0.2.99.2-1, 0.2.99.2-3, 0.2.99.3-1, 0.2.99.4-1, 0.2.99.4-2, 0.2.99.4-3, 0.2.99.4-3build1, 0.2.99.4-4, 0.2.99.4-4build1, 0.2.99.4-4build2, 0.2.99.4-4build3, 0.24.0+dfsg-1, 0.24.0+dfsg-1ubuntu0.1~esm1, 0.24.0+dfsg-1ubuntu0.1~esm4, 1.10.0-1, 1.10.0-2, 1.100.0-1ubuntu1, 1.11.0-1, 1.11.0-1ubuntu0.1~esm2, 1.3.0-1, 1.39.0-1, 1.4.0-1, 1.47.0-2, 1.47.1-1, 1.48.0-1, 1.49.0-1, 1.49.2-1, 1.5.0-1, 1.5.1-1, 1.50.1-1, 1.50.2-1, 1.51.0-1, 1.52.0-1, 1.53.0-1, 1.6.0-1, 1.6.1-1, 1.7.0-2, 1.7.1-1, 1.7.2-1, 1.7.3-1, 1.8.0-1, 1.9.0-1, 1.9.1-1, 1.90.0-1
- Fixed versions
- 1.53.0-1ubuntu0.1~esm2
- CVEs
- CVE-2024-31208
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 31 Oct 2026, 01:07 UTC · Revision 1
Source evidence
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 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 1.105.1 or later. Some workarounds are available. One can ban the malicious users or ACL block servers from the rooms and/or leave the room and purge the room using the admin API.
osv:UBUNTU-CVE-2024-31208
synapse
Fixed versions: Not specified
matrix-synapse
Fixed versions: Not specified
synapse
Fixed versions: Not specified
matrix-synapse
Fixed versions: Not specified
synapse
Fixed versions: Not specified
synapse
Fixed versions: Not specified
matrix-synapse
Fixed versions: 1.53.0-1ubuntu0.1~esm2
matrix-synapse
Fixed versions: Not specified
synapse
Fixed versions: Not specified
synapse
Fixed versions: Not specified
synapse
Fixed versions: Not specified
synapse
Fixed versions: Not specified
Complete source record
{
"id": "c031789fc4746a01b77f0244e623e410aca1fd7b6b058fdeb7c576b79fea5c88",
"url": "https://osv.dev/vulnerability/UBUNTU-CVE-2024-31208",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "UBUNTU-CVE-2024-31208",
"summary": "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 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 1.105.1 or later. Some workarounds are available. One can ban the malicious users or ACL block servers from the rooms and/or leave the room and purge the room using the admin API.",
"evidence": "osv:UBUNTU-CVE-2024-31208",
"products": [
{
"name": {
"value": "synapse",
"evidence": "/affected/0/package/name"
},
"prerequisites": [],
"fixed_versions": [],
"affected_versions": [
{
"value": "0.2.99.1-1",
"evidence": "/affected/0/versions"
},
{
"value": "0.2.99.2-1",
"evidence": "/affected/0/versions"
}
]
},
{
"name": {
"value": "matrix-synapse",
"evidence": "/affected/1/package/name"
},
"prerequisites": [],
"fixed_versions": [],
"affected_versions": [
{
"value": "0.19.2+dfsg-6",
"evidence": "/affected/1/versions"
},
{
"value": "0.24.0+dfsg-1",
"evidence": "/affected/1/versions"
},
{
"value": "0.24.0+dfsg-1ubuntu0.1~esm1",
"evidence": "/affected/1/versions"
},
{
"value": "0.24.0+dfsg-1ubuntu0.1~esm4",
"evidence": "/affected/1/versions"
}
]
},
{
"name": {
"value": "synapse",
"evidence": "/affected/2/package/name"
},
"prerequisites": [],
"fixed_versions": [],
"affected_versions": [
{
"value": "0.2.99.2-3",
"evidence": "/affected/2/versions"
},
{
"value": "0.2.99.3-1",
"evidence": "/affected/2/versions"
},
{
"value": "0.2.99.4-1",
"evidence": "/affected/2/versions"
}
]
},
{
"name": {
"value": "matrix-synapse",
"evidence": "/affected/3/package/name"
},
"prerequisites": [],
"fixed_versions": [],
"affected_versions": [
{
"value": "1.3.0-1",
"evidence": "/affected/3/versions"
},
{
"value": "1.4.0-1",
"evidence": "/affected/3/versions"
},
{
"value": "1.5.0-1",
"evidence": "/affected/3/versions"
},
{
"value": "1.5.1-1",
"evidence": "/affected/3/versions"
},
{
"value": "1.6.0-1",
"evidence": "/affected/3/versions"
},
{
"value": "1.6.1-1",
"evidence": "/affected/3/versions"
},
{
"value": "1.7.0-2",
"evidence": "/affected/3/versions"
},
{
"value": "1.7.1-1",
"evidence": "/affected/3/versions"
},
{
"value": "1.7.2-1",
"evidence": "/affected/3/versions"
},
{
"value": "1.7.3-1",
"evidence": "/affected/3/versions"
},
{
"value": "1.8.0-1",
"evidence": "/affected/3/versions"
},
{
"value": "1.9.0-1",
"evidence": "/affected/3/versions"
},
{
"value": "1.9.1-1",
"evidence": "/affected/3/versions"
},
{
"value": "1.10.0-1",
"evidence": "/affected/3/versions"
},
{
"value": "1.10.0-2",
"evidence": "/affected/3/versions"
},
{
"value": "1.11.0-1",
"evidence": "/affected/3/versions"
},
{
"value": "1.11.0-1ubuntu0.1~esm2",
"evidence": "/affected/3/versions"
}
]
},
{
"name": {
"value": "synapse",
"evidence": "/affected/4/package/name"
},
"prerequisites": [],
"fixed_versions": [],
"affected_versions": [
{
"value": "0.2.99.4-2",
"evidence": "/affected/4/versions"
}
]
},
{
"name": {
"value": "synapse",
"evidence": "/affected/5/package/name"
},
"prerequisites": [],
"fixed_versions": [],
"affected_versions": [
{
"value": "0.2.99.4-3",
"evidence": "/affected/5/versions"
},
{
"value": "0.2.99.4-3build1",
"evidence": "/affected/5/versions"
}
]
},
{
"name": {
"value": "matrix-synapse",
"evidence": "/affected/6/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "1.53.0-1ubuntu0.1~esm2",
"evidence": "/affected/6/ranges"
}
],
"affected_versions": [
{
"value": "1.39.0-1",
"evidence": "/affected/6/versions"
},
{
"value": "1.47.0-2",
"evidence": "/affected/6/versions"
},
{
"value": "1.47.1-1",
"evidence": "/affected/6/versions"
},
{
"value": "1.48.0-1",
"evidence": "/affected/6/versions"
},
{
"value": "1.49.0-1",
"evidence": "/affected/6/versions"
},
{
"value": "1.49.2-1",
"evidence": "/affected/6/versions"
},
{
"value": "1.50.1-1",
"evidence": "/affected/6/versions"
},
{
"value": "1.50.2-1",
"evidence": "/affected/6/versions"
},
{
"value": "1.51.0-1",
"evidence": "/affected/6/versions"
},
{
"value": "1.52.0-1",
"evidence": "/affected/6/versions"
},
{
"value": "1.53.0-1",
"evidence": "/affected/6/versions"
}
]
},
{
"name": {
"value": "matrix-synapse",
"evidence": "/affected/7/package/name"
},
"prerequisites": [],
"fixed_versions": [],
"affected_versions": [
{
"value": "1.90.0-1",
"evidence": "/affected/7/versions"
},
{
"value": "1.100.0-1ubuntu1",
"evidence": "/affected/7/versions"
}
]
},
{
"name": {
"value": "synapse",
"evidence": "/affected/8/package/name"
},
"prerequisites": [],
"fixed_versions": [],
"affected_versions": [
{
"value": "0.2.99.4-4",
"evidence": "/affected/8/versions"
},
{
"value": "0.2.99.4-4build1",
"evidence": "/affected/8/versions"
},
{
"value": "0.2.99.4-4build2",
"evidence": "/affected/8/versions"
}
]
},
{
"name": {
"value": "synapse",
"evidence": "/affected/9/package/name"
},
"prerequisites": [],
"fixed_versions": [],
"affected_versions": [
{
"value": "0.2.99.4-4build2",
"evidence": "/affected/9/versions"
}
]
},
{
"name": {
"value": "synapse",
"evidence": "/affected/10/package/name"
},
"prerequisites": [],
"fixed_versions": [],
"affected_versions": [
{
"value": "0.2.99.4-4build3",
"evidence": "/affected/10/versions"
}
]
},
{
"name": {
"value": "synapse",
"evidence": "/affected/11/package/name"
},
"prerequisites": [],
"fixed_versions": [],
"affected_versions": [
{
"value": "0.2.99.4-4build2",
"evidence": "/affected/11/versions"
},
{
"value": "0.2.99.4-4build3",
"evidence": "/affected/11/versions"
}
]
}
],
"severity": "medium",
"structured": {
"id": "UBUNTU-CVE-2024-31208",
"aliases": [
"UBUNTU-CVE-2024-31208"
],
"metrics": [
{
"type": "CVSS_V3",
"score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H"
},
{
"type": "Ubuntu",
"score": "medium"
}
],
"affected": [
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
}
]
}
],
"package": {
"name": "synapse",
"purl": "pkg:deb/ubuntu/synapse?arch=source&distro=xenial",
"ecosystem": "Ubuntu:16.04:LTS"
},
"versions": [
"0.2.99.1-1",
"0.2.99.2-1"
],
"database_specific": {
"source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2024/UBUNTU-CVE-2024-31208.json"
},
"ecosystem_specific": {
"binaries": [
{
"binary_name": "synapse",
"binary_version": "0.2.99.2-1"
}
]
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
}
]
}
],
"package": {
"name": "matrix-synapse",
"purl": "pkg:deb/ubuntu/matrix-synapse?arch=source&distro=esm-apps%2Fbionic",
"ecosystem": "Ubuntu:Pro:18.04:LTS"
},
"versions": [
"0.19.2+dfsg-6",
"0.24.0+dfsg-1",
"0.24.0+dfsg-1ubuntu0.1~esm1",
"0.24.0+dfsg-1ubuntu0.1~esm4"
],
"database_specific": {
"source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2024/UBUNTU-CVE-2024-31208.json"
},
"ecosystem_specific": {
"binaries": [
{
"binary_name": "matrix-synapse",
"binary_version": "0.24.0+dfsg-1ubuntu0.1~esm4"
}
]
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
}
]
}
],
"package": {
"name": "synapse",
"purl": "pkg:deb/ubuntu/synapse?arch=source&distro=bionic",
"ecosystem": "Ubuntu:18.04:LTS"
},
"versions": [
"0.2.99.2-3",
"0.2.99.3-1",
"0.2.99.4-1"
],
"database_specific": {
"source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2024/UBUNTU-CVE-2024-31208.json"
},
"ecosystem_specific": {
"binaries": [
{
"binary_name": "synapse",
"binary_version": "0.2.99.4-1"
}
]
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
}
]
}
],
"package": {
"name": "matrix-synapse",
"purl": "pkg:deb/ubuntu/matrix-synapse?arch=source&distro=esm-apps%2Ffocal",
"ecosystem": "Ubuntu:Pro:20.04:LTS"
},
"versions": [
"1.3.0-1",
"1.4.0-1",
"1.5.0-1",
"1.5.1-1",
"1.6.0-1",
"1.6.1-1",
"1.7.0-2",
"1.7.1-1",
"1.7.2-1",
"1.7.3-1",
"1.8.0-1",
"1.9.0-1",
"1.9.1-1",
"1.10.0-1",
"1.10.0-2",
"1.11.0-1",
"1.11.0-1ubuntu0.1~esm2"
],
"database_specific": {
"source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2024/UBUNTU-CVE-2024-31208.json"
},
"ecosystem_specific": {
"binaries": [
{
"binary_name": "matrix-synapse",
"binary_version": "1.11.0-1ubuntu0.1~esm2"
}
]
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
}
]
}
],
"package": {
"name": "synapse",
"purl": "pkg:deb/ubuntu/synapse?arch=source&distro=focal",
"ecosystem": "Ubuntu:20.04:LTS"
},
"versions": [
"0.2.99.4-2"
],
"database_specific": {
"source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2024/UBUNTU-CVE-2024-31208.json"
},
"ecosystem_specific": {
"binaries": [
{
"binary_name": "synapse",
"binary_version": "0.2.99.4-2"
}
]
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
}
]
}
],
"package": {
"name": "synapse",
"purl": "pkg:deb/ubuntu/synapse?arch=source&distro=jammy",
"ecosystem": "Ubuntu:22.04:LTS"
},
"versions": [
"0.2.99.4-3",
"0.2.99.4-3build1"
],
"database_specific": {
"source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2024/UBUNTU-CVE-2024-31208.json"
},
"ecosystem_specific": {
"binaries": [
{
"binary_name": "synapse",
"binary_version": "0.2.99.4-3build1"
}
]
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "1.53.0-1ubuntu0.1~esm2"
}
]
}
],
"package": {
"name": "matrix-synapse",
"purl": "pkg:deb/ubuntu/matrix-synapse?arch=source&distro=esm-apps%2Fjammy",
"ecosystem": "Ubuntu:Pro:22.04:LTS"
},
"versions": [
"1.39.0-1",
"1.47.0-2",
"1.47.1-1",
"1.48.0-1",
"1.49.0-1",
"1.49.2-1",
"1.50.1-1",
"1.50.2-1",
"1.51.0-1",
"1.52.0-1",
"1.53.0-1"
],
"database_specific": {
"source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2024/UBUNTU-CVE-2024-31208.json"
},
"ecosystem_specific": {
"binaries": [
{
"binary_name": "matrix-synapse",
"binary_version": "1.53.0-1ubuntu0.1~esm2"
}
],
"availability": "Available with Ubuntu Pro: https://ubuntu.com/pro"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
}
]
}
],
"package": {
"name": "matrix-synapse",
"purl": "pkg:deb/ubuntu/matrix-synapse?arch=source&distro=noble",
"ecosystem": "Ubuntu:24.04:LTS"
},
"versions": [
"1.90.0-1",
"1.100.0-1ubuntu1"
],
"database_specific": {
"source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2024/UBUNTU-CVE-2024-31208.json"
},
"ecosystem_specific": {
"binaries": [
{
"binary_name": "matrix-synapse",
"binary_version": "1.100.0-1ubuntu1"
}
]
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
}
]
}
],
"package": {
"name": "synapse",
"purl": "pkg:deb/ubuntu/synapse?arch=source&distro=noble",
"ecosystem": "Ubuntu:24.04:LTS"
},
"versions": [
"0.2.99.4-4",
"0.2.99.4-4build1",
"0.2.99.4-4build2"
],
"database_specific": {
"source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2024/UBUNTU-CVE-2024-31208.json"
},
"ecosystem_specific": {
"binaries": [
{
"binary_name": "synapse",
"binary_version": "0.2.99.4-4build2"
}
]
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
}
]
}
],
"package": {
"name": "synapse",
"purl": "pkg:deb/ubuntu/synapse?arch=source&distro=questing",
"ecosystem": "Ubuntu:25.10"
},
"versions": [
"0.2.99.4-4build2"
],
"database_specific": {
"source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2024/UBUNTU-CVE-2024-31208.json"
},
"ecosystem_specific": {
"binaries": [
{
"binary_name": "synapse",
"binary_version": "0.2.99.4-4build2"
}
]
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
}
]
}
],
"package": {
"name": "synapse",
"purl": "pkg:deb/ubuntu/synapse?arch=source&distro=stonking",
"ecosystem": "Ubuntu:26.10"
},
"versions": [
"0.2.99.4-4build3"
],
"database_specific": {
"source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2024/UBUNTU-CVE-2024-31208.json"
},
"ecosystem_specific": {
"binaries": [
{
"binary_name": "synapse",
"binary_version": "0.2.99.4-4build3"
}
]
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
}
]
}
],
"package": {
"name": "synapse",
"purl": "pkg:deb/ubuntu/synapse?arch=source&distro=resolute",
"ecosystem": "Ubuntu:26.04:LTS"
},
"versions": [
"0.2.99.4-4build2",
"0.2.99.4-4build3"
],
"database_specific": {
"source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2024/UBUNTU-CVE-2024-31208.json"
},
"ecosystem_specific": {
"binaries": [
{
"binary_name": "synapse",
"binary_version": "0.2.99.4-4build3"
}
]
}
}
],
"modified": "2026-10-17T12:56:35.141191607Z",
"provider": "osv",
"upstream": [
"CVE-2024-31208"
],
"references": [
"https://ubuntu.com/security/CVE-2024-31208",
"https://www.cve.org/CVERecord?id=CVE-2024-31208",
"https://github.com/element-hq/synapse/security/advisories/GHSA-3h7q-rfh9-xm4v",
"https://github.com/element-hq/synapse/commit/55b0aa847a61774b6a3acdc4b177a20dc019f01a",
"https://github.com/element-hq/synapse/releases/tag/v1.105.1",
"https://ubuntu.com/security/notices/USN-7444-1"
]
},
"related_cves": [
{
"value": "CVE-2024-31208",
"evidence": "/upstream"
}
],
"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 355820,
"published_at": "2024-04-23T18:15:00+00:00"
}