posixshm: largepage shared memory objects not explicitly wired
Summary
| CVE | CVE-2026-49427 |
|---|---|
| State | PUBLISHED |
| Assigner | freebsd |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-08-19 06:17:41 UTC |
| Updated | 2026-08-19 06:17:41 UTC |
| 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. |
Risk And Classification
Problem Types: CWE-826 | CWE-826 CWE-826: Premature Release of Resource During Expected Lifetime
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | FreeBSD | FreeBSD | affected 15.1-RELEASE p1 release | Not specified |
| CNA | FreeBSD | FreeBSD | affected 15.0-RELEASE p11 release | Not specified |
| CNA | FreeBSD | FreeBSD | affected 14.4-RELEASE p7 release | Not specified |
| CNA | FreeBSD | FreeBSD | affected 14.3-RELEASE p16 release | Not specified |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| security.freebsd.org/advisories/FreeBSD-SA-26:44.posixshm.asc | [email protected] | security.freebsd.org | |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
Vendor Comments And Credit
Discovery Credit
CNA: Chris Jarrett-Davies of the OpenAI Codex Security Team (en)
There are currently no legacy QID mappings associated with this CVE.