High severity · published Oct 15, 2026
CVE-2026-101303
IPv6 UDP sendto(2) bypasses jail loopback restriction
7.5
CVSS
0.2%
EPSS
No
On KEV
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.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
None
Integrity
High
Availability
None
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.2% · higher than 11% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
FR
FreeBSD · FreeBSD
15.1-RELEASE before p4; 15.0-RELEASE before p14; 14.5-RELEASE before p1; 14.4-RELEASE before p10 · source: vendor, NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-101303
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-101303
Patch
https://security.freebsd.org/advisories/FreeBSD-SA-26:69.udp.asc
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