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.
History

Tue, 02 Jun 2026 15:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Thu, 28 May 2026 19:00:00 +0000

Type Values Removed Values Added
First Time appeared Element-hq
Element-hq synapse
Vendors & Products Element-hq
Element-hq synapse

Thu, 28 May 2026 17:00:00 +0000

Type Values Removed Values Added
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.
Title Synapse pagination denial of service
Weaknesses CWE-20
References
Metrics cvssV4_0

{'score': 5.1, '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'}


cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published:

Updated: 2026-06-02T14:51:34.553Z

Reserved: 2026-05-08T18:45:10.096Z

Link: CVE-2026-45076

cve-icon Vulnrichment

Updated: 2026-06-02T14:51:26.936Z

cve-icon NVD

Status : Undergoing Analysis

Published: 2026-05-28T17:16:31.590

Modified: 2026-05-28T18:03:16.223

Link: CVE-2026-45076

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-05-28T19:00:16Z