CVE-2026-45076: medium-severity vulnerability in element-hq synapse
Synapse pagination denial of service
Published · Updated
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13Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 5.1epss 0.4%
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.
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
Affected products
element-hq · synapseRelated CVEs — element-hq synapse
In the same product, most dangerous first.
CVE-2024-31208MEDIUMSynapse's V2 state resolution weakness allows DoS from remote room membersEPSS 1.5%CVE-2025-30355HIGHSynapse vulnerable to federation denial of service via malformed eventsEPSS 1.2%CVE-2024-52805HIGHSynapse allows unsupported content types to lead to memory exhaustionEPSS 0.7%CVE-2024-53863HIGHSynapse can be forced to thumbnail unexpected file formats, invoking external, potentially untrustworthy decodersEPSS 0.6%CVE-2024-37302HIGHSynapse denial of service through media disk space consumptionEPSS 0.6%CVE-2024-52815HIGHSynapse allows a a malformed invite to break the invitee's `/sync`EPSS 0.6%