{"id":"CVE-2026-45076","summary":"Synapse pagination denial of service","details":"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.","aliases":["GHSA-6qf2-7x63-mm6v","PYSEC-2026-194"],"modified":"2026-07-15T01:49:21.551756017Z","published":"2026-05-28T15:50:25.842Z","related":["CGA-jx7f-g5vj-6w3g","openSUSE-SU-2026:10898-1"],"database_specific":{"cwe_ids":["CWE-20"],"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/45xxx/CVE-2026-45076.json","cna_assigner":"GitHub_M"},"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/45xxx/CVE-2026-45076.json"},{"type":"ADVISORY","url":"https://github.com/element-hq/synapse/security/advisories/GHSA-6qf2-7x63-mm6v"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-45076"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/element-hq/synapse","events":[{"introduced":"0"},{"fixed":"d97b5b9e21681792d78c5d58243fc483c664b66e"}],"database_specific":{"extracted_events":[{"introduced":"0"},{"fixed":"1.152.1"}],"source":["AFFECTED_FIELD","CPE_RANGE"],"cpe":"cpe:2.3:a:element:synapse:*:*:*:*:*:*:*:*"}}],"versions":["v1.152.0","v1.152.0rc1","v1.151.0rc1","v1.150.0rc1","v1.147.0rc1","v1.146.0rc1","v1.143.0rc2","v1.143.0rc1","v1.142.0rc3","v1.142.0rc2","v1.142.0rc1","v1.138.0rc1","v1.137.0rc1","v1.136.0rc1","v1.135.0rc1","v1.133.0rc1","v1.130.0rc1","v1.128.0rc1","v1.127.0rc1","v1.126.0rc3","v1.126.0rc2","v1.126.0rc1","v1.124.0rc1","v1.123.0rc1","v1.121.0rc1","v1.116.0rc1","v1.115.0rc1","v1.114.0rc1","v1.112.0rc1","v1.111.0rc1","v1.106.0rc1","v1.105.0rc1","v1.104.0rc1","v1.103.0rc1","v1.101.0rc1","v1.100.0rc3","v1.100.0rc2","v1.100.0rc1","v1.99.0rc1","v1.98.0rc1","v1.95.0rc1","v1.94.0rc1","v1.90.0rc1","v1.88.0rc1","v1.87.0rc1","v1.84.0rc1","v1.81.0rc1","v1.79.0rc1","v1.78.0rc1","v1.76.0rc1","v1.75.0rc1","v1.63.0rc1","v1.62.0rc1","v1.52.0rc1","v1.49.0rc1","v1.40.0rc1","v1.36.0rc1","v1.35.0rc1","v1.34.0rc1","v1.32.0rc1","v1.31.0rc1","v1.30.0rc1","v1.29.0rc1","v1.27.0rc1","v1.24.0rc1","v1.23.0rc1","v1.17.0rc1","v1.18.0rc1","v1.16.0rc1","v1.15.0rc1","v1.14.0rc1","v1.12.0rc1","v1.6.0rc1","v1.11.0rc1","v1.3.0rc1","v1.1.0rc2","v1.1.0rc1","v1.10.0rc1","v1.9.0rc1","v1.9.0.dev2","v1.9.0.dev1","v1.8.0rc1","v1.5.0rc1","v1.4.0rc1","v0.99.5.1.dev0","v0.99.4rc1","v0.99.2rc1","v0.99.1rc1","hhs-8","hhs-7","hhs-6","hhs-5","hhs-3","hhs-2","hhs-1","v0.32.2","v0.32.0","v0.32.0rc1","v0.28.0-rc1","v0.25.0-rc1","v0.23.0-rc2","v0.23.0-rc1","v0.18.5","v0.18.4","v0.18.3","v0.18.2","v0.18.1","v0.18.0","v0.17.3","v0.17.2","v0.17.1","v0.17.0","v0.16.1-r1","v0.16.1","v0.16.0","v0.14.0","v0.13.3","v0.13.2","v0.13.1","v0.12.0","v0.11.1","v0.11.0-r2","v0.11.0-r1","v0.11.0","v0.10.0-r2","v0.10.0-r1","v0.10.0","v0.9.3","v0.9.2-r2","v0.9.2-r1","v0.9.2","v0.9.1","v0.9.0-r5","v0.9.0-r4","v0.9.0-r3","v0.9.0-r2","v0.9.0-r1","v0.9.0","v0.8.1-r4","v0.8.1-r3","v0.8.1-r2","v0.8.1-r1","v0.8.1","v0.8.0","v0.7.1-r4","v0.7.1-r3","v0.7.1-r2","v0.7.1-r1","v0.7.1","v0.7.0f","v0.7.0e","v0.7.0d","v0.7.0c","v0.7.0b","v0.7.0a","v0.7.0","v0.6.1f","v0.6.1e","v0.6.1d","v0.6.1c","v0.6.1b","v0.6.1a","v0.6.1","v0.6.0b","v0.6.0a","v0.6.0","v0.5.4a","v0.5.4","v0.5.3c","v0.5.3b","v0.5.3a","v0.5.3","v0.5.2","v0.5.1","v0.5.0","v0.4.2","v0.4.1","v0.3.4","v0.3.3","v0.3.0","v0.2.2","v0.2.1a","v0.2.1","v0.2.0"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-45076.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V4","score":"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"}]}