CVE-2026-45078
Synapse CPU starvation (Denial of Service)
5.5
MEDIUM
CVSS 3.1
EPSS 0.01%
Description
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.
How to fix CVE-2026-45078
To remediate CVE-2026-45078, upgrade the affected package to a fixed version below.
- —upgrade to 1.152.1-1 or later
- —upgrade to 1.152.1 or later
- —upgrade to 1.152.1 or later
Is CVE-2026-45078 being exploited?
Low — EPSS is 0.0%, meaning exploitation activity has not been observed at scale.
Affected packages (3)
- from 0, < 1.152.1-1
- from 0, < 1.152.1
- from 0, < 1.152.1
CVSS scores
| Source | Version | Severity | Vector |
|---|---|---|---|
| osv | CVSS 4.0 | — | CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N |
| osv | CVSS 3.1 | MEDIUM5.5 | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H |