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CVE-2026-101303NVD status: Analyzed

FreeBSD: Incorrectly Specified Destination in a Communication Channel

CVE-2026-101303 is a high-severity incorrectly specified destination in a communication channel vulnerability in FreeBSD, with a CVSS 3.1 base score of 7.5 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. The record lists versions p4, p14, p1 as the first without the flaw, so updating FreeBSD to one of those releases or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.21% chance of exploitation within 30 days, which is low compared with other CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Update FreeBSD to p4 or p14 or p1 or p10, whichever matches your release line, or a later version.
  2. Read the advisory on security.freebsd.org for workarounds and exact fixed builds.
  3. Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.

Affected products and versions

VendorProductAffected versionsFixed in
FreeBSDFreeBSD15.1-RELEASE up to, but not including, p4; 15.0-RELEASE up to, but not including, p14; 14.5-RELEASE up to, but not including, p1; 14.4-RELEASE up to, but not including, p10p4, p14, p1, p10

Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Attack vector
NetworkCan be exploited remotely over a network, including the internet.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
Privileges required
NoneNo account or login is needed.
User interaction
NoneNo action by a victim is required.
Scope
UnchangedImpact stays within the vulnerable component.
Confidentiality
NoneNo data is disclosed.
Integrity
HighData or code can be modified at will.
Availability
NoneAvailability is not affected.

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N. Scored by CISA (ADP).

Official 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.

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Incorrectly Specified Destination in a Communication Channel

The product creates a communication channel to initiate an outgoing request to an actor, but it does not correctly specify the intended destination for that actor.

More Incorrectly Specified Destination in a Communication Channel vulnerabilities (CWE-941)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: yes, technical impact: partial).
  3. Record last changed materially (score, affected products, status or references).

References

Other vulnerabilities in FreeBSD

All FreeBSD vulnerabilities

Recent Incorrectly Specified Destination in a Communication Channel vulnerabilities

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