CVE-2026-45078

MEDIUM

Synapse CPU starvation (Denial of Service)

Title source: cna
STIX 2.1

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.

References (1)

Core 1
Core References

Scores

CVSS v3 5.5
EPSS 0.0013
EPSS Percentile 2.8%
Attack Vector LOCAL
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

CISA SSVC

Vulnrichment
Exploitation none
Automatable no
Technical Impact partial

Details

CWE
CWE-770
Status published
Products (3)
element/synapse < 1.152.1
element-hq/synapse < 1.152.1
pypi/matrix-synapse 0 - 1.152.1PyPI
Published May 28, 2026
Tracked Since May 28, 2026