CVE-2026-49427

High

Description

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.

SeverityHigh

CVSS8.8

Exploit probability—

Product

Freebsd

PublishedAug 19, 2026

First seenAug 19, 2026

Weakness typeCWE-826CWE-826

How to fix

Vendor advisories

security.freebsd.org/advisories/FreeBSD-SA-26:44.posixshm.asc

Affected products

Product	Affected versions	Fixed in
freebsd freebsd	14.3, 14.4, 15.0, 15.1	—

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