CVE catalog
CVE-2021-21394
UBUNTU-CVE-2021-21394
- Severity
- Unknown
- Published
- Updated
- Source
- [NVD] · [CVE record]
- EPSS
- 1.54% · Oct 25, 2026
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 third-party identifiers could cause excessive use of disk space and memory leading to resource exhaustion. Note that the groups feature is not part of the Matrix specification and the chosen maximum lengths are arbitrary. Not all clients might abide by them. Refer to referenced GitHub security advisory for additional details including workarounds.
Vulnerable and fixed packages
Distribution-reported package versions and fixes. These do not depend on matching against the OpenFactory package catalog.
| Distribution | Package | Release | Version | Status |
|---|---|---|---|---|
| Ubuntu | matrix-synapse | pro | 0.19.2+dfsg-6 | vulnerable |
| Ubuntu | matrix-synapse | pro | 0.24.0+dfsg-1 | vulnerable |
| Ubuntu | matrix-synapse | pro | 0.24.0+dfsg-1ubuntu0.1~esm1 | vulnerable |
| Ubuntu | matrix-synapse | pro | 0.24.0+dfsg-1ubuntu0.1~esm4 | vulnerable |
| Ubuntu | matrix-synapse | pro | 1.3.0-1 | vulnerable |
| Ubuntu | matrix-synapse | pro | 1.4.0-1 | vulnerable |
| Ubuntu | matrix-synapse | pro | 1.5.0-1 | vulnerable |
| Ubuntu | matrix-synapse | pro | 1.5.1-1 | vulnerable |
| Ubuntu | matrix-synapse | pro | 1.6.0-1 | vulnerable |
| Ubuntu | matrix-synapse | pro | 1.6.1-1 | vulnerable |
| Ubuntu | matrix-synapse | pro | 1.7.0-2 | vulnerable |
| Ubuntu | matrix-synapse | pro | 1.7.1-1 | vulnerable |
| Ubuntu | matrix-synapse | pro | 1.7.2-1 | vulnerable |
| Ubuntu | matrix-synapse | pro | 1.7.3-1 | vulnerable |
| Ubuntu | matrix-synapse | pro | 1.8.0-1 | vulnerable |
| Ubuntu | matrix-synapse | pro | 1.9.0-1 | vulnerable |
| Ubuntu | matrix-synapse | pro | 1.9.1-1 | vulnerable |
| Ubuntu | matrix-synapse | pro | 1.10.0-1 | vulnerable |
| Ubuntu | matrix-synapse | pro | 1.10.0-2 | vulnerable |
| Ubuntu | matrix-synapse | pro | 1.11.0-1 | vulnerable |
| Ubuntu | matrix-synapse | pro | 1.11.0-1ubuntu0.1~esm2 | vulnerable |
| Ubuntu | matrix-synapse | pro | 1.39.0-1 | vulnerable |
| Ubuntu | matrix-synapse | pro | 1.47.0-2 | vulnerable |
| Ubuntu | matrix-synapse | pro | 1.47.1-1 | vulnerable |
| Ubuntu | matrix-synapse | pro | 1.48.0-1 | vulnerable |
| Ubuntu | matrix-synapse | pro | 1.49.0-1 | vulnerable |
| Ubuntu | matrix-synapse | pro | 1.49.2-1 | vulnerable |
| Ubuntu | matrix-synapse | pro | 1.50.1-1 | vulnerable |
| Ubuntu | matrix-synapse | pro | 1.50.2-1 | vulnerable |
| Ubuntu | matrix-synapse | pro | 1.51.0-1 | vulnerable |
| Ubuntu | matrix-synapse | pro | 1.52.0-1 | vulnerable |
| Ubuntu | matrix-synapse | pro | 1.53.0-1 | vulnerable |
| Ubuntu | matrix-synapse | pro | 1.53.0-1ubuntu0.1~esm2 | vulnerable |
Fixed-version evidence
OpenFactory catalog packages
No matching packages in this catalog.
Observed: