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Jail filesystem root escape in FreeBSD via file descriptor passing

Priority MEDIUM 48CWE-273Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Impact type
—
Confidentiality · integrity · availability
High · High · High
Fix status
Fixed

Attack profile from CVSS 3.1 · CISA ADP. Fix status from CNA.

Summary

FreeBSD releases from 15.1-RELEASE before p4, 15.0-RELEASE before p14, 14.5-RELEASE before p1 and 14.4-RELEASE before p10 are affected. SCM_RIGHTS file descriptor passing does not preserve FD_RESOLVE_BENEATH when a descriptor is transferred, so a process can clear the restriction by sending the descriptor to itself over a Unix domain socket. A process in a jail that receives a directory file descriptor from another jail can escape the jail's filesystem root (CWE-281).

Written with Claude Haiku 5.5 from the sources below · 2026-10-28

Description from the CNA

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.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00268 19th percentileScored 2026-11-07
Fix Fixed FreeBSD (FreeBSD): p4, p14, p1 +1

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
Yes
Technical impact
Total

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
FreeBSDFreeBSD15.1-RELEASE to before p4; 15.0-RELEASE to before p14; 14.5-RELEASE to before p1; 14.4-RELEASE to before p10p4, p14, p1, p10Patch availableCNA
  • FreeBSD VendorFreeBSD Affected 15.1-RELEASE to before p4; 15.0-RELEASE to before p14; 14.5-RELEASE to before p1; 14.4-RELEASE to before p10 Fixed in p4, p14, p1, p10 Patch available CNA

CPE configurations NVD · 29

CPEVersionsRoleVendor
cpe:2.3:o:freebsd:freebsd:14.4:-:*:*:*:*:*:*14.4VulnerableFreeBSD
cpe:2.3:o:freebsd:freebsd:14.4:p1:*:*:*:*:*:*14.4 p1VulnerableFreeBSD
cpe:2.3:o:freebsd:freebsd:14.4:p2:*:*:*:*:*:*14.4 p2VulnerableFreeBSD
cpe:2.3:o:freebsd:freebsd:14.4:p3:*:*:*:*:*:*14.4 p3VulnerableFreeBSD
cpe:2.3:o:freebsd:freebsd:14.4:p4:*:*:*:*:*:*14.4 p4VulnerableFreeBSD
cpe:2.3:o:freebsd:freebsd:14.4:p5:*:*:*:*:*:*14.4 p5VulnerableFreeBSD
cpe:2.3:o:freebsd:freebsd:14.4:p6:*:*:*:*:*:*14.4 p6VulnerableFreeBSD
cpe:2.3:o:freebsd:freebsd:14.4:p7:*:*:*:*:*:*14.4 p7VulnerableFreeBSD
cpe:2.3:o:freebsd:freebsd:14.4:p8:*:*:*:*:*:*14.4 p8VulnerableFreeBSD
cpe:2.3:o:freebsd:freebsd:14.4:p9:*:*:*:*:*:*14.4 p9VulnerableFreeBSD
  • cpe:2.3:o:freebsd:freebsd:14.4:-:*:*:*:*:*:* Versions 14.4 Vulnerable ·FreeBSD
  • cpe:2.3:o:freebsd:freebsd:14.4:p1:*:*:*:*:*:* Versions 14.4 p1 Vulnerable ·FreeBSD
  • cpe:2.3:o:freebsd:freebsd:14.4:p2:*:*:*:*:*:* Versions 14.4 p2 Vulnerable ·FreeBSD
  • cpe:2.3:o:freebsd:freebsd:14.4:p3:*:*:*:*:*:* Versions 14.4 p3 Vulnerable ·FreeBSD
  • cpe:2.3:o:freebsd:freebsd:14.4:p4:*:*:*:*:*:* Versions 14.4 p4 Vulnerable ·FreeBSD
  • cpe:2.3:o:freebsd:freebsd:14.4:p5:*:*:*:*:*:* Versions 14.4 p5 Vulnerable ·FreeBSD
  • cpe:2.3:o:freebsd:freebsd:14.4:p6:*:*:*:*:*:* Versions 14.4 p6 Vulnerable ·FreeBSD
  • cpe:2.3:o:freebsd:freebsd:14.4:p7:*:*:*:*:*:* Versions 14.4 p7 Vulnerable ·FreeBSD
  • cpe:2.3:o:freebsd:freebsd:14.4:p8:*:*:*:*:*:* Versions 14.4 p8 Vulnerable ·FreeBSD
  • cpe:2.3:o:freebsd:freebsd:14.4:p9:*:*:*:*:*:* Versions 14.4 p9 Vulnerable ·FreeBSD
Show 19 more CPE
CPEVersionsRoleVendor
cpe:2.3:o:freebsd:freebsd:14.5:-:*:*:*:*:*:*14.5VulnerableFreeBSD
cpe:2.3:o:freebsd:freebsd:15.0:-:*:*:*:*:*:*15.0VulnerableFreeBSD
cpe:2.3:o:freebsd:freebsd:15.0:p1:*:*:*:*:*:*15.0 p1VulnerableFreeBSD
cpe:2.3:o:freebsd:freebsd:15.0:p10:*:*:*:*:*:*15.0 p10VulnerableFreeBSD
cpe:2.3:o:freebsd:freebsd:15.0:p11:*:*:*:*:*:*15.0 p11VulnerableFreeBSD
cpe:2.3:o:freebsd:freebsd:15.0:p12:*:*:*:*:*:*15.0 p12VulnerableFreeBSD
cpe:2.3:o:freebsd:freebsd:15.0:p13:*:*:*:*:*:*15.0 p13VulnerableFreeBSD
cpe:2.3:o:freebsd:freebsd:15.0:p2:*:*:*:*:*:*15.0 p2VulnerableFreeBSD
cpe:2.3:o:freebsd:freebsd:15.0:p3:*:*:*:*:*:*15.0 p3VulnerableFreeBSD
cpe:2.3:o:freebsd:freebsd:15.0:p4:*:*:*:*:*:*15.0 p4VulnerableFreeBSD
cpe:2.3:o:freebsd:freebsd:15.0:p5:*:*:*:*:*:*15.0 p5VulnerableFreeBSD
cpe:2.3:o:freebsd:freebsd:15.0:p6:*:*:*:*:*:*15.0 p6VulnerableFreeBSD
cpe:2.3:o:freebsd:freebsd:15.0:p7:*:*:*:*:*:*15.0 p7VulnerableFreeBSD
cpe:2.3:o:freebsd:freebsd:15.0:p8:*:*:*:*:*:*15.0 p8VulnerableFreeBSD
cpe:2.3:o:freebsd:freebsd:15.0:p9:*:*:*:*:*:*15.0 p9VulnerableFreeBSD
cpe:2.3:o:freebsd:freebsd:15.1:-:*:*:*:*:*:*15.1VulnerableFreeBSD
cpe:2.3:o:freebsd:freebsd:15.1:p1:*:*:*:*:*:*15.1 p1VulnerableFreeBSD
cpe:2.3:o:freebsd:freebsd:15.1:p2:*:*:*:*:*:*15.1 p2VulnerableFreeBSD
cpe:2.3:o:freebsd:freebsd:15.1:p3:*:*:*:*:*:*15.1 p3VulnerableFreeBSD
  • cpe:2.3:o:freebsd:freebsd:14.5:-:*:*:*:*:*:* Versions 14.5 Vulnerable ·FreeBSD
  • cpe:2.3:o:freebsd:freebsd:15.0:-:*:*:*:*:*:* Versions 15.0 Vulnerable ·FreeBSD
  • cpe:2.3:o:freebsd:freebsd:15.0:p1:*:*:*:*:*:* Versions 15.0 p1 Vulnerable ·FreeBSD
  • cpe:2.3:o:freebsd:freebsd:15.0:p10:*:*:*:*:*:* Versions 15.0 p10 Vulnerable ·FreeBSD
  • cpe:2.3:o:freebsd:freebsd:15.0:p11:*:*:*:*:*:* Versions 15.0 p11 Vulnerable ·FreeBSD
  • cpe:2.3:o:freebsd:freebsd:15.0:p12:*:*:*:*:*:* Versions 15.0 p12 Vulnerable ·FreeBSD
  • cpe:2.3:o:freebsd:freebsd:15.0:p13:*:*:*:*:*:* Versions 15.0 p13 Vulnerable ·FreeBSD
  • cpe:2.3:o:freebsd:freebsd:15.0:p2:*:*:*:*:*:* Versions 15.0 p2 Vulnerable ·FreeBSD
  • cpe:2.3:o:freebsd:freebsd:15.0:p3:*:*:*:*:*:* Versions 15.0 p3 Vulnerable ·FreeBSD
  • cpe:2.3:o:freebsd:freebsd:15.0:p4:*:*:*:*:*:* Versions 15.0 p4 Vulnerable ·FreeBSD
  • cpe:2.3:o:freebsd:freebsd:15.0:p5:*:*:*:*:*:* Versions 15.0 p5 Vulnerable ·FreeBSD
  • cpe:2.3:o:freebsd:freebsd:15.0:p6:*:*:*:*:*:* Versions 15.0 p6 Vulnerable ·FreeBSD
  • cpe:2.3:o:freebsd:freebsd:15.0:p7:*:*:*:*:*:* Versions 15.0 p7 Vulnerable ·FreeBSD
  • cpe:2.3:o:freebsd:freebsd:15.0:p8:*:*:*:*:*:* Versions 15.0 p8 Vulnerable ·FreeBSD
  • cpe:2.3:o:freebsd:freebsd:15.0:p9:*:*:*:*:*:* Versions 15.0 p9 Vulnerable ·FreeBSD
  • cpe:2.3:o:freebsd:freebsd:15.1:-:*:*:*:*:*:* Versions 15.1 Vulnerable ·FreeBSD
  • cpe:2.3:o:freebsd:freebsd:15.1:p1:*:*:*:*:*:* Versions 15.1 p1 Vulnerable ·FreeBSD
  • cpe:2.3:o:freebsd:freebsd:15.1:p2:*:*:*:*:*:* Versions 15.1 p2 Vulnerable ·FreeBSD
  • cpe:2.3:o:freebsd:freebsd:15.1:p3:*:*:*:*:*:* Versions 15.1 p3 Vulnerable ·FreeBSD

Remediation

Upgrade FreeBSD to 15.1-RELEASE p4, 15.0-RELEASE p14, 14.5-RELEASE p1 or 14.4-RELEASE p10.

Written with Claude Haiku 5.5 from the sources below · 2026-10-28

  • Fix · CNA FreeBSD (FreeBSD) Fixed in p4, p14, p1, p10

Fixed in the same release

Records fixed by the same vendor advisory or release, as the CNA lists them.

  • Advisory ·

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

    3 records Highest priority Priority MEDIUM 2 MEDIUM, 1 LOW

    Other records, highest priority first

    • TI-2026-74627 Multiple jail filesystem root escapesPriority MEDIUM 40
    • TI-2026-74626 Jail filesystem root escapes in FreeBSD fdescfsPriority LOW 32

Timeline

  1. 2026-10-15 Threatist record created from CVE-2026-101306
  2. 2026-10-16 Alias added: GHSA-3c4j-rmc7-2x5m
  3. 2026-10-16 CVSS score added · CISA ADP
  4. 2026-10-16 CISA SSVC decision points changed
  5. 2026-10-16 Priority changed: LOW → MEDIUM

References

  • TI-2011-04182 Buffer overflow in libtelnet/encrypt.c in telnetd in FreeBSD 7.3 through 9.0, MIT… CVSS 2.0HIGH 10.0
  • TI-2007-03684 Integer overflow in print-bgp.c in the BGP dissector in tcpdump 3.9.6 and earlier allows… CVSS 3.1CRITICAL 9.8
  • TI-2002-00376 Integer overflow in xdr_array function in RPC servers for operating systems that use… CVSS 3.1CRITICAL 9.8
  • TI-2024-05929 Openssh: regresshion - race condition in ssh allows rce/dos CVSS 3.1HIGH 8.1
  • TI-2003-00437 Off-by-one error in the fb_realpath() function, as derived from the realpath function in… CVSS 3.1CRITICAL 9.8
  • TI-2003-00642 The prescan function in Sendmail 8.12.9 allows remote attackers to execute arbitrary code… CVSS 2.0HIGH 10.0
See all 576 →

Sources