high5.5
CVE-2026-45078
Synapse is an open source Matrix homeserver implementation.
Impact
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.
Affected packages
| Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|
| pip | matrix-synapse | < 1.152.1 | 1.152.1 |
Affected products
| Vendor | Product | Affected versions |
|---|---|---|
| Element | Synapse | before 1.152.1 |
Weakness classification
References
- NVD record
- CVE.org record
- GitHub advisory
- https://github.com/advisories/GHSA-8q93-326v-3m7g
- https://github.com/element-hq/synapse/security/advisories/GHSA-8q93-326v-3m7g
- https://github.com/element-hq/synapse/issues/19394
- https://github.com/element-hq/synapse/commit/3f58bc50dfba5768ee43ce48c5e74c25ba0b078a
- https://nvd.nist.gov/vuln/detail/CVE-2026-45078
- https://github.com/pypa/advisory-database/tree/main/vulns/matrix-synapse/PYSEC-2026-191.yaml