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TI-2026-33063 Aliases CVE-2026-45256GHSA-hvc9-hvw8-q2fx

Missing permission check in thr_kill2(2)

Priority LOW 24CWE-269Published · Updated

Key facts

Attack vector
Local
Privileges required
Low
User interaction
None
Attack complexity
Low
Impact type
Privilege escalation
Confidentiality · integrity · availability
None · None · High
Fix status
Fixed

Attack profile from CVSS 3.1 · CISA ADP. Fix status from CNA. Impact type from CWE-269.

Summary

When used to deliver a signal to a specific thread, thr_kill2(2) called p_cansignal() to determine whether the operation was permitted but did not check the result before delivering the signal. The signal was sent even when the permission check failed. The system call returned the resulting error to the caller, but by then the signal had already been delivered. The missing check allows an unprivileged local user who knows or can guess a target's process and thread IDs to send any signal to a process they would not normally be permitted to signal, including processes owned by other users or by root. The same check enforces jail boundaries, so a jailed process can signal processes on the host or in other jails. Thread IDs are allocated globally and sequentially, and so can be discovered by brute force with no visibility into the target. An attacker can stop or terminate arbitrary processes, including critical system daemons, resulting in a Denial of Service (DoS).

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00122 2nd percentileScored 2026-11-07
Fix Fixed FreeBSD (FreeBSD): p10, p6, p15

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
Technical impact
Partial

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

Affected products

VendorProductAffected versionsFixed inStatusSource
FreeBSDFreeBSD15.0-RELEASE to before p10; 14.4-RELEASE to before p6; 14.3-RELEASE to before p15p10, p6, p15Patch availableCNA
  • FreeBSD VendorFreeBSD Affected 15.0-RELEASE to before p10; 14.4-RELEASE to before p6; 14.3-RELEASE to before p15 Fixed in p10, p6, p15 Patch available CNA

CPE configurations NVD · 33

CPEVersionsRoleVendor
cpe:2.3:o:freebsd:freebsd:14.3:-:*:*:*:*:*:*14.3VulnerableFreeBSD
cpe:2.3:o:freebsd:freebsd:14.3:p1:*:*:*:*:*:*14.3 p1VulnerableFreeBSD
cpe:2.3:o:freebsd:freebsd:14.3:p10:*:*:*:*:*:*14.3 p10VulnerableFreeBSD
cpe:2.3:o:freebsd:freebsd:14.3:p11:*:*:*:*:*:*14.3 p11VulnerableFreeBSD
cpe:2.3:o:freebsd:freebsd:14.3:p12:*:*:*:*:*:*14.3 p12VulnerableFreeBSD
cpe:2.3:o:freebsd:freebsd:14.3:p13:*:*:*:*:*:*14.3 p13VulnerableFreeBSD
cpe:2.3:o:freebsd:freebsd:14.3:p14:*:*:*:*:*:*14.3 p14VulnerableFreeBSD
cpe:2.3:o:freebsd:freebsd:14.3:p2:*:*:*:*:*:*14.3 p2VulnerableFreeBSD
cpe:2.3:o:freebsd:freebsd:14.3:p3:*:*:*:*:*:*14.3 p3VulnerableFreeBSD
cpe:2.3:o:freebsd:freebsd:14.3:p4:*:*:*:*:*:*14.3 p4VulnerableFreeBSD
  • cpe:2.3:o:freebsd:freebsd:14.3:-:*:*:*:*:*:* Versions 14.3 Vulnerable ·FreeBSD
  • cpe:2.3:o:freebsd:freebsd:14.3:p1:*:*:*:*:*:* Versions 14.3 p1 Vulnerable ·FreeBSD
  • cpe:2.3:o:freebsd:freebsd:14.3:p10:*:*:*:*:*:* Versions 14.3 p10 Vulnerable ·FreeBSD
  • cpe:2.3:o:freebsd:freebsd:14.3:p11:*:*:*:*:*:* Versions 14.3 p11 Vulnerable ·FreeBSD
  • cpe:2.3:o:freebsd:freebsd:14.3:p12:*:*:*:*:*:* Versions 14.3 p12 Vulnerable ·FreeBSD
  • cpe:2.3:o:freebsd:freebsd:14.3:p13:*:*:*:*:*:* Versions 14.3 p13 Vulnerable ·FreeBSD
  • cpe:2.3:o:freebsd:freebsd:14.3:p14:*:*:*:*:*:* Versions 14.3 p14 Vulnerable ·FreeBSD
  • cpe:2.3:o:freebsd:freebsd:14.3:p2:*:*:*:*:*:* Versions 14.3 p2 Vulnerable ·FreeBSD
  • cpe:2.3:o:freebsd:freebsd:14.3:p3:*:*:*:*:*:* Versions 14.3 p3 Vulnerable ·FreeBSD
  • cpe:2.3:o:freebsd:freebsd:14.3:p4:*:*:*:*:*:* Versions 14.3 p4 Vulnerable ·FreeBSD
Show 23 more CPE
CPEVersionsRoleVendor
cpe:2.3:o:freebsd:freebsd:14.3:p5:*:*:*:*:*:*14.3 p5VulnerableFreeBSD
cpe:2.3:o:freebsd:freebsd:14.3:p6:*:*:*:*:*:*14.3 p6VulnerableFreeBSD
cpe:2.3:o:freebsd:freebsd:14.3:p7:*:*:*:*:*:*14.3 p7VulnerableFreeBSD
cpe:2.3:o:freebsd:freebsd:14.3:p8:*:*:*:*:*:*14.3 p8VulnerableFreeBSD
cpe:2.3:o:freebsd:freebsd:14.3:p9:*:*:*:*:*:*14.3 p9VulnerableFreeBSD
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:rc1:*:*:*:*:*:*14.4 rc1VulnerableFreeBSD
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: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:rc2:*:*:*:*:*:*15.1 rc2VulnerableFreeBSD
  • cpe:2.3:o:freebsd:freebsd:14.3:p5:*:*:*:*:*:* Versions 14.3 p5 Vulnerable ·FreeBSD
  • cpe:2.3:o:freebsd:freebsd:14.3:p6:*:*:*:*:*:* Versions 14.3 p6 Vulnerable ·FreeBSD
  • cpe:2.3:o:freebsd:freebsd:14.3:p7:*:*:*:*:*:* Versions 14.3 p7 Vulnerable ·FreeBSD
  • cpe:2.3:o:freebsd:freebsd:14.3:p8:*:*:*:*:*:* Versions 14.3 p8 Vulnerable ·FreeBSD
  • cpe:2.3:o:freebsd:freebsd:14.3:p9:*:*:*:*:*:* Versions 14.3 p9 Vulnerable ·FreeBSD
  • 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:rc1:*:*:*:*:*:* Versions 14.4 rc1 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: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:rc2:*:*:*:*:*:* Versions 15.1 rc2 Vulnerable ·FreeBSD

Remediation

  • Fix · CNA FreeBSD (FreeBSD) Fixed in p10, p6, p15

Fixed in the same release

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

  • Release ·

    FreeBSD p10, p15, p6

    2 records Highest priority Priority HIGH 1 HIGH, 1 LOW

    Other records, highest priority first

    • TI-2026-33064 Arbitrary file overwrite via the KTLS receive pathPriority HIGH 69
    Show all 2 records →

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-45256
  2. 2026-10-03 Alias added: GHSA-hvc9-hvw8-q2fx

References

Advisory 1

  • 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

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences