CVE-2026-49427 (GCVE-0-2026-49427)

Vulnerability from cvelistv5 – Published: 2026-08-19 05:56 – Updated: 2026-08-20 18:35
VLAI
Title
posixshm: largepage shared memory objects not explicitly wired
Summary
Pages belonging to largepage shared memory objects were not explicitly wired. When sendfile(2) transmitted such an object with the SF_NOCACHE flag, it freed the underlying pages after transmission even though existing mappings still referred to them. An unprivileged local user can abuse the bug to access freed kernel memory. This can be exploited to escalate privileges.
Severity
8.8 (High)
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/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 2026-08-20 03:56 UTC
CWE
  • CWE-826 - Premature Release of Resource During Expected Lifetime
Assigner
References
Impacted products
Vendor Product Version CPE status
FreeBSD FreeBSD Affected: 15.1-RELEASE , < p1 (release)
Affected: 15.0-RELEASE , < p11 (release)
Affected: 14.4-RELEASE , < p7 (release)
Affected: 14.3-RELEASE , < p16 (release)
guessed Create a notification for this product.
Date Public
2026-06-30 20:00
Credits
Chris Jarrett-Davies of the OpenAI Codex Security Team
Show details on NVD website
To clipboard 

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Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

Sightings

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Nomenclature

  • 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.
  • Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
  • Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
  • Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
  • Not confirmed: The user expressed doubt about the validity of the vulnerability.
  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.


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