CVE-2026-58087 (GCVE-0-2026-58087)

Vulnerability from cvelistv5 – Published: 2026-08-19 07:47 – Updated: 2026-08-19 11:48
VLAI
Title
Heap out-of-bounds access in semctl(2)
Summary
The 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.
Severity
7.8 (High)
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
SSVC
Exploitation: none Automatable: no Technical Impact: total
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-08-19 11:47 UTC
CWE
  • CWE-191 - Integer Underflow (Wrap or Wraparound)
  • CWE-125 - Out-of-bounds Read
  • CWE-787 - Out-of-bounds Write
Assigner
References
Impacted products
Vendor Product Version CPE status
FreeBSD FreeBSD Affected: 15.1-RELEASE , < p2 (release)
Affected: 15.0-RELEASE , < p12 (release)
Affected: 14.4-RELEASE , < p8 (release)
guessed Create a notification for this product.
Date Public
2026-07-29 22:40
Credits
Maik Muench of Secfault Security
Show details on NVD website
To clipboard 

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  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
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  • Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
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  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.


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