{"id":"CVE-2026-45076","state":"PUBLISHED","title":"Synapse pagination denial of service","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.","publishedAt":"2026-05-28T15:50:25.842Z","updatedAt":"2026-06-02T14:51:34.553Z","severity":{"score":5.1,"label":"Medium","version":"4.0","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","source":"GitHub_M"},"assigner":"GitHub_M","products":["element-hq synapse"],"affected":[{"vendor":"element-hq","product":"synapse","versions":[{"version":"< 1.152.1","status":"affected"}]}],"references":["https://github.com/element-hq/synapse/security/advisories/GHSA-6qf2-7x63-mm6v"],"weaknesses":["CWE-20"],"ingestedAt":"2026-10-29T20:12:07.131Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/45xxx/CVE-2026-45076.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-45076","state":"PUBLISHED","datePublished":"2026-05-28T15:50:25.842Z","dateUpdated":"2026-06-02T14:51:34.553Z","assignerShortName":"GitHub_M","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateReserved":"2026-05-08T18:45:10.096Z"},"containers":{"cna":{"title":"Synapse pagination denial of service","descriptions":[{"lang":"en","value":"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."}],"affected":[{"vendor":"element-hq","product":"synapse","versions":[{"version":"< 1.152.1","status":"affected"}]}],"references":[{"url":"https://github.com/element-hq/synapse/security/advisories/GHSA-6qf2-7x63-mm6v","name":"https://github.com/element-hq/synapse/security/advisories/GHSA-6qf2-7x63-mm6v","tags":["x_refsource_CONFIRM"]}],"metrics":[{"cvssV4_0":{"attackVector":"NETWORK","attackComplexity":"LOW","attackRequirements":"NONE","privilegesRequired":"HIGH","userInteraction":"NONE","vulnConfidentialityImpact":"NONE","vulnIntegrityImpact":"NONE","vulnAvailabilityImpact":"LOW","subConfidentialityImpact":"NONE","subIntegrityImpact":"NONE","subAvailabilityImpact":"NONE","baseScore":5.1,"baseSeverity":"MEDIUM","vectorString":"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","version":"4.0"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-20","lang":"en","description":"CWE-20: Improper Input Validation","type":"CWE"}]}],"providerMetadata":{"shortName":"GitHub_M","orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateUpdated":"2026-05-28T15:50:25.842Z"},"source":{"advisory":"GHSA-6qf2-7x63-mm6v","discovery":"UNKNOWN"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-06-02T14:51:22.795858Z","id":"CVE-2026-45076","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-06-02T14:51:34.553Z"}}]}}}