CVE-2026-49427CWE-826

CVE-2026-49427

High · published August 19, 2026

CVSS v3.1
8.8
EPSS
0%
Percentile
20.1
In the wild
Unconfirmed
What it is

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.

The record
Technical detail
CVSS v3.1
8.8 · HIGH
Vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
CVSS v4.0
Not supplied
EPSS
0.00279 · 20.1th percentile
Weakness
CWE-826 · Premature Release of Resource During Expected Lifetime
Published
2026-08-19T10:17Z
Affected products (38)
ProductVersionsFixed in
freebsd/freebsdall versions—
freebsd/freebsdall versions—
freebsd/freebsdall versions—
freebsd/freebsdall versions—
freebsd/freebsdall versions—
freebsd/freebsdall versions—
freebsd/freebsdall versions—
freebsd/freebsdall versions—
freebsd/freebsdall versions—
freebsd/freebsdall versions—
freebsd/freebsdall versions—
freebsd/freebsdall versions—
freebsd/freebsdall versions—
freebsd/freebsdall versions—
freebsd/freebsdall versions—
freebsd/freebsdall versions—
freebsd/freebsdall versions—
freebsd/freebsdall versions—
freebsd/freebsdall versions—
freebsd/freebsdall versions—
freebsd/freebsdall versions—
freebsd/freebsdall versions—
freebsd/freebsdall versions—
freebsd/freebsdall versions—
freebsd/freebsdall versions—
freebsd/freebsdall versions—
freebsd/freebsdall versions—
freebsd/freebsdall versions—
freebsd/freebsdall versions—
freebsd/freebsdall versions—
freebsd/freebsdall versions—
freebsd/freebsdall versions—
freebsd/freebsdall versions—
freebsd/freebsdall versions—
freebsd/freebsdall versions—
freebsd/freebsdall versions—
freebsd/freebsdall versions—
freebsd/freebsdall versions—
References (1)
https://security.freebsd.org/advisories/FreeBSD-SA-26:44.posixshm.asc · [email protected]
EPSS history
Timeline
  • 19 AUG 05:56Z
    posixshm: largepage shared memory objects not explicitly wired
    cvelistv5