CVE-2026-45076

LOW

Synapse pagination denial of service

Title source: cna
STIX 2.1

Description

Synapse is an open source Matrix homeserver implementation. Prior to 1.152.1, in federated rooms, malicious homeservers can craft room events in such a way that prevents Synapse from providing full history to paginating clients. Clients could therefore fail to display room history. This vulnerability is fixed in 1.152.1.

References (1)

Core 1
Core References

Scores

CVSS v3 2.7
EPSS 0.0037
EPSS Percentile 28.4%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:L

CISA SSVC

Vulnrichment
Exploitation none
Automatable no
Technical Impact partial

Details

CWE
CWE-20
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