How severe is CVE-2024-52815?

CVE-2024-52815 has a CVSS 3.x base score of 5.3, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability low.

Is CVE-2024-52815 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (42nd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2024-52815?

CVE-2024-52815 affects Matrix Synapse. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2024-52815?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

Does CVE-2024-52815 have an EU (EUVD) identifier?

Yes. CVE-2024-52815 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2024-3463.

When was CVE-2024-52815 published?

CVE-2024-52815 was published on 2024-12-03 and last updated on 2026-06-17.

CVE-2024-52815

CVE-2024-52815 is a medium-severity vulnerability in Matrix Synapse with a CVSS 3.x base score of 5.3. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-20.

Key facts

Severity: Medium (CVSS 3.x base score 5.3)
CVSS v4: 8.7
EPSS exploit prediction: 1% (42nd percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2024-3463
Weakness: CWE-20
Affected product: Matrix Synapse
Published: 2024-12-03
Last modified: 2026-06-17

Description

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.

Frequently asked questions

What is CVE-2024-52815?: 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.
How severe is CVE-2024-52815?: CVE-2024-52815 has a CVSS 3.x base score of 5.3, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability low.
Is CVE-2024-52815 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (42nd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2024-52815?: CVE-2024-52815 affects Matrix Synapse. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2024-52815?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2024-52815 have an EU (EUVD) identifier?: Yes. CVE-2024-52815 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2024-3463.
When was CVE-2024-52815 published?: CVE-2024-52815 was published on 2024-12-03 and last updated on 2026-06-17.

References

https://github.com/element-hq/synapse/security/advisories/GHSA-f3r3-h2mq-hx2h

Affected products (1)

cpe:2.3:a:matrix:synapse:*:*:*:*:*:*:*:*

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