Description

A heap-buffer-overflow vulnerability is possible in mvfst via a specially crafted message during a QUIC session. This issue affects mvfst versions prior to v2025.07.07.00.

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CVSS v3.1 Score

8.1

HIGH

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:H

References

Other References

https://github.com/facebook/mvfst/commit/65b297332191de6e867c4a3139a233fc84c0e7e0 https://www.facebook.com/security/advisories/cve-2025-30403

Frequently Asked Questions

What is CVE-2025-30403? +

A heap-buffer-overflow vulnerability is possible in mvfst via a specially crafted message during a QUIC session. This issue affects mvfst versions prior to v2025.07.07.00. It has a CVSS v3.1 base score of 8.1 (HIGH).

How severe is CVE-2025-30403? +

CVE-2025-30403 has a CVSS v3.1 score of 8.1 out of 10, rated HIGH. This is a high-severity vulnerability that should be prioritized for patching.

How do I check if I'm vulnerable to CVE-2025-30403? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.