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CVE-2026-101303

FreeBSD: IPv6 UDP sendto(2) bypasses jail loopback restriction

FreeBSD FreeBSDOperating systems
Open in ThreatlineRecord JSON
CVSS
7.5High
ExploitationNo known exploitationNot in CISA KEV, which does not prove it is unexploitedCISA KEV
Exploit odds (EPSS)0.36%Chance of exploitation activity in the next 30 days, higher than 28% of CVEs. Scored 23 Oct 2026FIRST EPSS
Fixed inNone listedNo source names a fixed version. Check the vendor advisory below
Published15 Oct 2026Updated 16 Oct 2026CVE List

What fixes it

No source in this snapshot names a fixed version. The vendor advisories under References are the place to check.

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.

Text from CVE List

Affected versions 4

  • FreeBSDaffected: 15.1-RELEASE before p4CVE List
  • FreeBSDaffected: 15.0-RELEASE before p14CVE List
  • FreeBSDaffected: 14.5-RELEASE before p1CVE List
  • FreeBSDaffected: 14.4-RELEASE before p10CVE List

References 1