CVE-2026-101303

IPv6 UDP sendto(2) bypasses jail loopback restriction

State: Published
Severity: 7.5 High
Published: Oct 15, 2026
Updated: Oct 16, 2026
Reserved: Sep 28, 2026

Description

The IPv6 UDP send path for unconnected sockets did not apply the jail policy of rewriting a loopback destination address to the jail's primary IPv6 address.

A process in a classic (non-VNET) jail can send UDP datagrams to services listening on the host's IPv6 loopback address, bypassing jail network isolation.

Scores

CVSS	Score	Vector	Source
3.1	7.5 High	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N	CISA-ADP

Weaknesses

CWE-941 Incorrectly Specified Destination in a Communication Channel

Affected Products

Product	Versions
FreeBSDFreeBSD	15.1-RELEASE to before p4Affected 15.0-RELEASE to before p14Affected 14.5-RELEASE to before p1Affected 14.4-RELEASE to before p10Affected

References

https://security.freebsd.org/advisories/FreeBSD-SA-26:69.udp.ascvendor-advisory

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