Vulnerability · Published Aug 19, 2026 · Assigned by freebsd
CVE-2026-49427posixshm: largepage shared memory objects not explicitly wired
High 8.8
In plain English
A high-severity security flaw in FreeBSD from FreeBSD. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.5% (higher than 43% of all known vulnerabilities).
Severity (CVSS 3.1)8.8High
Exploit odds (30 days)0.5%top 56.8% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known
Official 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.
Affected products (as reported)
Weakness: CWE-826 · Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H