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CVE-2026-101303

IPv6 UDP sendto(2) bypasses jail loopback restriction

HIGH
7.5
CVSS Score
Published: October 15, 2026 at 06:58 AM UTC
Updated: October 20, 2026 at 12:17 AM UTC
1 product affected across 1 vendorFreeBSD

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Severity
HIGH7.5
Exploit prediction
EPSS 0.2%
SSVC
No known exploit

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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

Patch and advisory references

References (1)

Vendor AdvisoryPatch
Source: cverecord
https://security.freebsd.org/advisories/FreeBSD-SA-26:69.udp.asc

SSVC — Action Prioritization

SSVCNo known exploitAutomatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

7.5HIGHCISA-ADP
Attack Vector
NETWORK
Complexity
LOW
Privileges
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
HIGH
Availability
NONE
Vector?

Quick Info

StatusANALYZED
CWE
CWE-941

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