What is CVE-2025-30403?

CVE-2025-30403 is a high-severity vulnerability in Facebook Mvfst. CVSS score: 8.1/10. Published 2025-07-11.

How severe is CVE-2025-30403?

High severity. CVSS v3 base score is 8.1 out of 10.

Vulnerability in Facebook Mvfst

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.

EPSS: 0.003 (20.6th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 8.1 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:H.

Affected products

Facebook Mvfst — versions v2025.03.24.00

References

cve-assign@fb.com (x_refsource_CONFIRM)
cve-assign@fb.com (x_refsource_CONFIRM)

Frequently asked questions

What is CVE-2025-30403?: CVE-2025-30403 is a high-severity vulnerability in Facebook Mvfst. CVSS score: 8.1/10. Published 2025-07-11.
How severe is CVE-2025-30403?: High severity. CVSS v3 base score is 8.1 out of 10.