CVE-2024-37303

MEDIUMNVD 5.35.3—
EchelonGraph scoreMEDIUM confidence

This medium-severity CVE scores 5.3 under NVD CVSS v3. EPSS exploit probability: 0.3%, top 43% of all CVEs by exploit prediction. GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).

Triggered by: NVD CVSS baseline
Sources: epss, nvd
5.3
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS: 0%CVSS: 5.3Exploit: NoneExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

Synapse is an open-source Matrix homeserver. Synapse before version 1.106 allows, by design, unauthenticated remote participants to trigger a download and caching of remote media from a remote homeserver to the local media repository. Such content then also becomes available for download from the local homeserver in an unauthenticated way. The implication is that unauthenticated remote adversaries can use this functionality to plant problematic content into the media repository. Synapse 1.106 introduces a partial mitigation in the form of new endpoints which require authentication for media downloads. The unauthenticated endpoints will be frozen in a future release, closing the attack vector.

CVSS v3
5.3
EG Score
5.3(medium)
EPSS
33.8%
KEV
Not listed

Published

December 3, 2024

Last Modified

August 26, 2025

References (2)

Vendor Advisories for CVE-2024-37303(1)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Affected Packages

(1 across 1 ecosystem)
PyPI(1)
PackageVulnerable rangeFixed inDependents
matrix-synapse0.33.5 ... 1.99.0rc1 (378 versions)1.106.0—

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 9× in last 7d / 44× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

  1. 2026-07-11 08:26 UTCEPSS rescore
  2. 2026-07-11 08:26 UTCEPSS rescore
  3. 2026-07-09 19:09 UTCEPSS rescore
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  10. 2026-07-05 02:29 UTCEPSS rescore
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  12. 2026-07-01 15:05 UTCEPSS rescore
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  15. 2026-06-28 14:06 UTCEPSS rescore
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  17. 2026-06-28 04:55 UTCEPSS rescore
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  19. 2026-06-27 03:07 UTCEPSS rescore
  20. 2026-06-27 03:07 UTCEPSS rescore
  21. 2026-06-25 15:16 UTCOSV refresh
  22. 2026-06-25 13:49 UTCEPSS rescore
  23. 2026-06-24 14:04 UTCEPSS rescore
  24. 2026-06-24 14:04 UTCEPSS rescore
  25. 2026-06-23 21:32 UTCEPSS rescore
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  1. 2026-06-23 21:32 UTCEPSS rescore
  2. 2026-06-22 14:25 UTCEPSS rescore
  3. 2026-06-22 14:25 UTCEPSS rescore
  4. 2026-06-21 14:55 UTCEPSS rescore
  5. 2026-06-21 14:55 UTCEPSS rescore
  6. 2026-06-21 01:58 UTCEPSS rescore
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  8. 2026-06-19 19:25 UTCEPSS rescore
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  10. 2026-06-18 17:52 UTCEPSS rescore
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  17. 2026-06-13 22:59 UTCEPSS rescore
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  19. 2026-06-12 23:11 UTCEPSS rescore
  20. 2026-06-11 13:59 UTCEPSS rescore
  21. 2026-06-10 22:17 UTCEPSS rescore
  22. 2026-06-10 13:21 UTCEPSS rescore
  23. 2026-06-08 14:16 UTCEPSS rescore
  24. 2026-06-08 05:28 UTCOSV refresh
  25. 2026-06-07 15:24 UTCEPSS rescore
  26. 2026-06-07 15:24 UTCEPSS rescore
  27. 2026-06-06 13:46 UTCEPSS rescore
  28. 2026-06-06 13:46 UTCEPSS rescore
  29. 2026-06-05 22:46 UTCEPSS rescore
  30. 2026-06-05 22:46 UTCEPSS rescore
  31. 2026-06-05 06:09 UTCEPSS rescore
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  35. 2026-06-02 20:12 UTCEPSS rescore
  36. 2026-06-01 13:51 UTCEPSS rescore
  37. 2026-06-01 13:51 UTCEPSS rescore
  38. 2026-05-31 22:30 UTCEPSS rescore
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  40. 2026-05-31 00:15 UTCEPSS rescore
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  42. 2026-05-29 13:43 UTCEPSS rescore
  43. 2026-05-28 13:44 UTCEPSS rescore
  44. 2026-05-28 13:44 UTCEPSS rescore
  45. 2026-05-28 13:44 UTCEPSS rescore
  46. 2026-05-27 13:40 UTCEPSS rescore
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  48. 2026-05-27 13:40 UTCEPSS rescore
  49. 2026-05-26 13:43 UTCEPSS rescore
  50. 2026-05-26 13:43 UTCEPSS rescore
  51. 2026-05-26 07:18 UTCEPSS rescore
  52. 2026-05-26 07:18 UTCEPSS rescore
  53. 2026-05-26 07:18 UTCEPSS rescore
  54. 2026-05-23 17:04 UTCEG score recompute

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2024-37303?
CVE-2024-37303 is a medium vulnerability published on December 3, 2024. Synapse is an open-source Matrix homeserver. Synapse before version 1.106 allows, by design, unauthenticated remote participants to trigger a download and caching of remote media from a remote homeserver to the local media repository. Such content then also becomes available for download from the…
When was CVE-2024-37303 disclosed?
CVE-2024-37303 was first published in the National Vulnerability Database on December 3, 2024, with the most recent update on August 26, 2025. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2024-37303 actively exploited?
CVE-2024-37303 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 33.8% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2024-37303?
CVE-2024-37303 has a CVSS v3 base score of 5.3 (NVD).
How do I remediate CVE-2024-37303?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2024-37303, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

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