Description
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 Synapse 1.95.1 or 1.96.0rc1 to receive a patch. As a workaround, the `federation_domain_whitelist` can be used to limit federation traffic with a homeserver.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| matrix-org | synapse | < 1.95.1 | — |
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu Pro 22.04 LTS | matrix-synapse | 1.53.0-1ubuntu0.1~esm2 | USN-7444-1 |
| Ubuntu Pro 20.04 LTS | matrix-synapse | 1.11.0-1ubuntu0.1~esm2 | USN-7444-1 |
| Ubuntu Pro 18.04 LTS | matrix-synapse | 0.24.0+dfsg-1ubuntu0.1~esm4 | USN-7444-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | matrix-synapse | 1.95.1-1.1 | openSUSE-SU-2024:13392-1 |
Alpine
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.24 | synapse | 1.95.1-r0 | — |
| Alpine v3.23 | synapse | 1.95.1-r0 | — |
| Alpine v3.22 | synapse | 1.95.1-r0 | — |
| Alpine v3.21 | synapse | 1.95.1-r0 | — |
| Alpine v3.20 | synapse | 1.95.1-r0 | — |
Show 2 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.19 | synapse | 1.95.1-r0 | — |
| Alpine v3.18 | synapse | 1.95.1-r0 | — |
Affected packages
| Ecosystem | Package | Affected | Fixed | Record |
|---|---|---|---|---|
| PyPI | matrix-synapse | < 1.95.1 | 1.95.1 | GHSA-mp92-3jfm-3575 |
Advisories 2
- USN-7444-1 matrix-synapse vulnerabilities Ubuntu Security Notices (USN) · Apr 27, 2026
- openSUSE-SU-2024:13392-1 matrix-synapse-1.95.1-1.1 on GA media SUSE / openSUSE Security Updates · Feb 4, 2026
References
- https://github.com/matrix-org/synapse/security/advisories/GHSA-mp92-3jfm-3575
- https://github.com/matrix-org/synapse/commit/daec55e1fe120c564240c5386e77941372bf458f
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/VH3RNC5ZPQZ4OKPSL4E6BBJSZOQLGDEY/
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/2IDEEZMFJBDLTFHQUTZRJJNCOZGQ2ZVS/
- https://security.gentoo.org/glsa/202401-12