VulnerabilityDeferred

CVE-2025-30403

A heap-buffer-overflow vulnerability is possible in mvfst via a specially crafted message during a QUIC session.

HIGH 8.1EPSS 0.29%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (0.29%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

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.

CVSS 3.1: 8.1 HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:H
EPSS: 0.29% probability · 21th percentile
CISA KEV: Not listed
Source: cve-assign@fb.com

References

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

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.