What is CVE-2024-52805?

CVE-2024-52805 is a high-severity vulnerability in Element-Hq Synapse, classified under Allocation of Resources Without Limits or Throttling. CVSS score: 7.5/10. Published 2024-12-03.

How severe is CVE-2024-52805?

High severity. CVSS v3 base score is 7.5 out of 10.

Resource exhaustion in Element-Hq Synapse

CVE-2024-52805

Synapse is an open-source Matrix homeserver. In Synapse before 1.120.1, multipart/form-data requests can in certain configurations transiently increase memory consumption beyond expected levels while processing the request, which can be used to amplify denial of service attacks. Synapse 1.120.1 resolves the issue by denying requests with unsupported multipart/form-data content type.

Published 2024-12-03 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

EPSS exploit prediction

EPSS: 0.007 (52.7th percentile), scored 2026-09-29.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 53rd percentile — 52.7% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.007 · newest: 0.007 · change: +0.000

Affected products

Element-Hq Synapse — versions < 1.120.1
Matrix Synapse

Weakness classification (CWE)

CWE-770 — Allocation of Resources Without Limits or Throttling

References

github.com/element-hq/synapse/security/advisories/GHSA-rfq8-j7rh-8hf2 (Vendor Advisory)
github.com/twisted/twisted/issues/4688 (Issue Tracking)
github.com/twisted/twisted/issues/4688 (Issue Tracking)

Frequently asked questions

What is CVE-2024-52805?: CVE-2024-52805 is a high-severity vulnerability in Element-Hq Synapse, classified under Allocation of Resources Without Limits or Throttling. CVSS score: 7.5/10. Published 2024-12-03.
How severe is CVE-2024-52805?: High severity. CVSS v3 base score is 7.5 out of 10.