CVE-2021-29627: Freebsd

High severity, CVSS 7.8. EPSS: 0.7% chance of exploitation in the next 30 days.

In FreeBSD 13.0-STABLE before n245050, 12.2-STABLE before r369525, 13.0-RC4 before p0, and 12.2-RELEASE before p6, listening socket accept filters implementing the accf_create callback incorrectly freed a process supplied argument string. Additional operations on the socket can lead to a double free or use after free.

Affected products

• Freebsd Freebsd: from 12.0, before 12.2 (fixed in 12.2); version 12.2 only; version 13.0 only

Published 2021-04-07. Last modified 2026-06-17.