CVE-2026-45076CWE-20

Synapse pagination denial of service

Medium · published May 28, 2026

CVSS v4.0
5.1
EPSS
0%
Percentile
31.4
In the wild
Unconfirmed
What it is

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.

The record
Technical detail
CVSS v4.0
5.1 · MEDIUM
Vector
CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N
EPSS
0.00385 · 31.4th percentile
Weakness
CWE-20 · Improper Input Validation
Published
2026-05-28T15:50Z
EPSS history
Timeline
  • 28 MAY 15:50Z
    Synapse pagination denial of service
    cvelistv5