CVE-2024-52815: high-severity vulnerability in element-hq synapse
Synapse allows a a malformed invite to break the invitee's `/sync`
Published
E-mail alert when it lands in KEV, gets a public PoC or its score goes up.
21Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 8.7epss 0.6%
Synapse is an open-source Matrix homeserver. Synapse versions before 1.120.1 fail to properly validate invites received over federation. This vulnerability allows a malicious server to send a specially crafted invite that disrupts the invited user's /sync functionality. Synapse 1.120.1 rejects such invalid invites received over federation and restores the ability to sync for affected users.
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/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-2025-61672MEDIUMSynapse: Invalid device keys degrade federation functionalityEPSS 0.5%