CVE-2026-45078 MEDIUM

CVE-2026-45078: Synapse CPU starvation (Denial of Service)

Vendor Element-Hq
Product synapse
Weakness CWE-770 · Uncontrolled resource consumption
Published May 28, 2026
Last update May 29, 2026
View on NVD All CVEs

CVSS base score

6.8/10
Attack vector Local
Attack complexity Low
Privileges required Low
User interaction None
Confidentiality —
Integrity —

CVSS vector

CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

What the vulnerability does

01Description

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.

Key dates

02Disclosure timeline

May 28, 2026 CVE published
May 29, 2026 Record updated