Heap out-of-bounds access in semctl(2)

MITRE NVD CVE.ORG JSON API

Summary

CVECVE-2026-58087
StatePUBLISHED
Assignerfreebsd
Source PriorityCVE Program / NVD first with legacy fallback
Published2026-08-19 08:17:12 UTC
Updated2026-08-31 15:07:33 UTC
DescriptionThe GETALL and SETALL commands in semctl(2) recorded the number of semaphores in the target set, dropped the lock protecting the set, allocated a buffer sized for that count, and reacquired the lock. A sequence-number check was used to verify that the set had not been replaced in the interim, but the sequence number wraps after 0x8000 create/destroy cycles. By rapidly destroying and recreating semaphore sets at the same index, another process can cause the sequence number to wrap, allowing a set with a different number of semaphores to pass validation. The subsequent copy then reads or writes past the end of the allocated buffer. An unprivileged local user can trigger out-of-bounds reads and writes on kernel heap memory, potentially leading to privilege escalation.

Risk And Classification

Primary CVSS: v3.1 7.8 HIGH from ADP

CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

EPSS: 0.001210000 probability, percentile 0.021390000 (date 2026-09-01)

Problem Types: CWE-125 | CWE-191 | CWE-787 | CWE-191 CWE-191: Integer Underflow (Wrap or Wraparound) | CWE-125 CWE-125: Out-of-bounds Read | CWE-787 CWE-787: Out-of-bounds Write

VersionSourceTypeScoreSeverityVector
3.1ADPDECLARED7.8HIGHCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
3.1134c704f-9b21-4f2e-91b3-4a467353bcc0Secondary7.8HIGHCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

CVSS v3.1 Breakdown

Attack Vector
Local
Attack Complexity
Low
Privileges Required
None
User Interaction
Required
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

NVD Known Affected Configurations (CPE 2.3)

TypeVendorProductVersionUpdateEditionLanguage
Operating System Freebsd Freebsd 14.4 - All All
Operating System Freebsd Freebsd 14.4 p1 All All
Operating System Freebsd Freebsd 14.4 p2 All All
Operating System Freebsd Freebsd 14.4 p3 All All
Operating System Freebsd Freebsd 14.4 p4 All All
Operating System Freebsd Freebsd 14.4 p5 All All
Operating System Freebsd Freebsd 14.4 p6 All All
Operating System Freebsd Freebsd 14.4 p7 All All
Operating System Freebsd Freebsd 14.4 rc1 All All
Operating System Freebsd Freebsd 15.0 - All All
Operating System Freebsd Freebsd 15.0 p1 All All
Operating System Freebsd Freebsd 15.0 p10 All All
Operating System Freebsd Freebsd 15.0 p11 All All
Operating System Freebsd Freebsd 15.0 p2 All All
Operating System Freebsd Freebsd 15.0 p3 All All
Operating System Freebsd Freebsd 15.0 p4 All All
Operating System Freebsd Freebsd 15.0 p5 All All
Operating System Freebsd Freebsd 15.0 p6 All All
Operating System Freebsd Freebsd 15.0 p7 All All
Operating System Freebsd Freebsd 15.0 p8 All All
Operating System Freebsd Freebsd 15.0 p9 All All
Operating System Freebsd Freebsd 15.1 - All All
Operating System Freebsd Freebsd 15.1 p1 All All
Operating System Freebsd Freebsd 15.1 rc2 All All
Operating System Freebsd Freebsd 15.1 rc3-p1 All All

Vendor Declared Affected Products

SourceVendorProductVersionPlatforms
CNA FreeBSD FreeBSD affected 15.1-RELEASE p2 release Not specified
CNA FreeBSD FreeBSD affected 15.0-RELEASE p12 release Not specified
CNA FreeBSD FreeBSD affected 14.4-RELEASE p8 release Not specified

References

ReferenceSourceLinkTags
security.freebsd.org/advisories/FreeBSD-SA-26:54.sysvsem.asc [email protected] security.freebsd.org Vendor Advisory, Mailing List
CVE Program record CVE.ORG www.cve.org canonical
NVD vulnerability detail NVD nvd.nist.gov canonical, analysis

Vendor Comments And Credit

Discovery Credit

CNA: Maik Muench of Secfault Security (en)

© CVE.report 2026

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