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TI-2026-74609 Aliases CVE-2026-58098

Out-of-bounds heap access in FreeBSD semop(2)

Priority LOW 37CWE-787Published · Updated

Key facts

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

Attack profile from CVSS 3.1 · CISA ADP. Fix status from CNA. Impact type from CWE-787 and the CVSS impact.

Summary

FreeBSD from 15.1-RELEASE before p4, from 15.0-RELEASE before p14, from 14.5-RELEASE before p1, and from 14.4-RELEASE before p10 is affected. When semop(2) wakes after blocking, it checks a 15-bit sequence number to detect a removed semaphore set, and that counter can wrap around (CWE-787). An unprivileged local user can trigger an out-of-bounds access on kernel heap memory, potentially leading to privilege escalation.

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

Description from the CNA

When semop(2) blocks waiting for a semaphore condition, it releases the per-set lock and sleeps. Upon waking, it checks the sequence number embedded in the semaphore set's IPC identifier to detect whether the set was removed while the caller was asleep. This sequence number is only 15 bits wide. If enough semaphore sets are created and destroyed in the same table slot while a caller is blocked, the counter wraps around, and semop(2) may falsely conclude that the original set still exists. The subsequent access to a semaphore within the set may then be out of bounds. An unprivileged local user can trigger an out-of-bounds access on kernel heap memory, potentially leading to privilege escalation.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00114 1st percentileScored 2026-11-07
Fix Fixed FreeBSD (FreeBSD): p4, p14, p1 +1

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
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

Apply the fix in FreeBSD p4 for 15.1-RELEASE, p14 for 15.0-RELEASE, p1 for 14.5-RELEASE, and p10 for 14.4-RELEASE.

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.

  • Release ·

    FreeBSD p1, p10 and 2 more versions

    3 records Highest priority Priority LOW 3 LOW

    Other records, highest priority first

    • TI-2026-74625 IPv6 UDP sendto bypasses jail loopback restriction in FreeBSDPriority LOW 38
    • TI-2026-74624 FreeBSD kernel TLS receive path off-by-one causes remote kernel panicPriority LOW 28
    Show all 3 records →

Timeline

  1. 2026-10-15 Threatist record created from CVE-2026-58098
  2. 2026-10-16 CVSS score added · CISA ADP
  3. 2026-10-16 CISA SSVC decision points changed

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