CVE-2026-101306

CVE-2026-101306 is a critical-severity vulnerability in Freebsd with a CVSS 3.x base score of 9.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-273.

Key facts

• Severity: Critical (CVSS 3.x base score 9.8)
• EPSS exploit prediction: 0% (18th percentile)
• Actively exploited: Not listed in CISA KEV
• Weakness: CWE-273
• Affected product: Freebsd
• Published: 2026-10-15
• Last modified: 2026-10-20

Description

SCM_RIGHTS file descriptor passing did not preserve FD_RESOLVE_BENEATH when a descriptor was transferred. A process could clear the restriction by sending the descriptor to itself over a Unix domain socket. A process in a jail that has received a directory file descriptor from another jail can use these techniques to escape the jail's filesystem root restriction.

Frequently asked questions

What is CVE-2026-101306?

SCM_RIGHTS file descriptor passing did not preserve FD_RESOLVE_BENEATH when a descriptor was transferred. A process could clear the restriction by sending the descriptor to itself over a Unix domain socket. A process in a jail that has received a directory file descriptor from another jail can use these techniques to escape the jail's filesystem root restriction.

How severe is CVE-2026-101306?

CVE-2026-101306 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2026-101306 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (18th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-101306?

CVE-2026-101306 primarily affects Freebsd. In total, 29 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2026-101306?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.

When was CVE-2026-101306 published?

CVE-2026-101306 was published on 2026-10-15 and last updated on 2026-10-20.

References

• https://security.freebsd.org/advisories/FreeBSD-SA-26:66.jail.asc

Affected products (29)

• cpe:2.3:o:freebsd:freebsd:14.4:-:*:*:*:*:*:*
• cpe:2.3:o:freebsd:freebsd:14.4:p1:*:*:*:*:*:*
• cpe:2.3:o:freebsd:freebsd:14.4:p2:*:*:*:*:*:*
• cpe:2.3:o:freebsd:freebsd:14.4:p3:*:*:*:*:*:*
• cpe:2.3:o:freebsd:freebsd:14.4:p4:*:*:*:*:*:*
• cpe:2.3:o:freebsd:freebsd:14.4:p5:*:*:*:*:*:*
• cpe:2.3:o:freebsd:freebsd:14.4:p6:*:*:*:*:*:*
• cpe:2.3:o:freebsd:freebsd:14.4:p7:*:*:*:*:*:*
• cpe:2.3:o:freebsd:freebsd:14.4:p8:*:*:*:*:*:*
• cpe:2.3:o:freebsd:freebsd:14.4:p9:*:*:*:*:*:*
• cpe:2.3:o:freebsd:freebsd:14.5:-:*:*:*:*:*:*
• cpe:2.3:o:freebsd:freebsd:15.0:-:*:*:*:*:*:*
• cpe:2.3:o:freebsd:freebsd:15.0:p1:*:*:*:*:*:*
• cpe:2.3:o:freebsd:freebsd:15.0:p10:*:*:*:*:*:*
• cpe:2.3:o:freebsd:freebsd:15.0:p11:*:*:*:*:*:*
• cpe:2.3:o:freebsd:freebsd:15.0:p12:*:*:*:*:*:*
• cpe:2.3:o:freebsd:freebsd:15.0:p13:*:*:*:*:*:*
• cpe:2.3:o:freebsd:freebsd:15.0:p2:*:*:*:*:*:*
• cpe:2.3:o:freebsd:freebsd:15.0:p3:*:*:*:*:*:*
• cpe:2.3:o:freebsd:freebsd:15.0:p4:*:*:*:*:*:*
• cpe:2.3:o:freebsd:freebsd:15.0:p5:*:*:*:*:*:*
• cpe:2.3:o:freebsd:freebsd:15.0:p6:*:*:*:*:*:*
• cpe:2.3:o:freebsd:freebsd:15.0:p7:*:*:*:*:*:*
• cpe:2.3:o:freebsd:freebsd:15.0:p8:*:*:*:*:*:*
• cpe:2.3:o:freebsd:freebsd:15.0:p9:*:*:*:*:*:*
• cpe:2.3:o:freebsd:freebsd:15.1:-:*:*:*:*:*:*
• cpe:2.3:o:freebsd:freebsd:15.1:p1:*:*:*:*:*:*
• cpe:2.3:o:freebsd:freebsd:15.1:p2:*:*:*:*:*:*
• cpe:2.3:o:freebsd:freebsd:15.1:p3:*:*:*:*:*:*

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