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 | 2026-09-01 20:06:01 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
Primary CVSS: v3.1 8.8 HIGH from ADP
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
EPSS: 0.002790000 probability, percentile 0.200490000 (date 2026-09-03)
Problem Types: CWE-826 | CWE-826 CWE-826: Premature Release of Resource During Expected Lifetime
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 3.1 | ADP | DECLARED | 8.8 | HIGH | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H |
| 3.1 | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | Secondary | 8.8 | HIGH | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H |
CVSS v3.1 Breakdown
Attack Vector
NetworkAttack Complexity
LowPrivileges Required
LowUser Interaction
NoneScope
UnchangedConfidentiality
HighIntegrity
HighAvailability
HighCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
NVD Known Affected Configurations (CPE 2.3)
| Type | Vendor | Product | Version | Update | Edition | Language |
|---|---|---|---|---|---|---|
| Operating System | Freebsd | Freebsd | 14.3 | - | All | All |
| Operating System | Freebsd | Freebsd | 14.3 | p1 | All | All |
| Operating System | Freebsd | Freebsd | 14.3 | p10 | All | All |
| Operating System | Freebsd | Freebsd | 14.3 | p11 | All | All |
| Operating System | Freebsd | Freebsd | 14.3 | p12 | All | All |
| Operating System | Freebsd | Freebsd | 14.3 | p13 | All | All |
| Operating System | Freebsd | Freebsd | 14.3 | p14 | All | All |
| Operating System | Freebsd | Freebsd | 14.3 | p15 | All | All |
| Operating System | Freebsd | Freebsd | 14.3 | p2 | All | All |
| Operating System | Freebsd | Freebsd | 14.3 | p3 | All | All |
| Operating System | Freebsd | Freebsd | 14.3 | p4 | All | All |
| Operating System | Freebsd | Freebsd | 14.3 | p5 | All | All |
| Operating System | Freebsd | Freebsd | 14.3 | p6 | All | All |
| Operating System | Freebsd | Freebsd | 14.3 | p7 | All | All |
| Operating System | Freebsd | Freebsd | 14.3 | p8 | All | All |
| Operating System | Freebsd | Freebsd | 14.3 | p9 | All | All |
| Operating System | Freebsd | Freebsd | 14.4 | - | All | All |
| Operating System | Freebsd | Freebsd | 14.4 | p1 | All | All |
| Operating System | Freebsd | Freebsd | 14.4 | p2 | All | All |
| Operating System | Freebsd | Freebsd | 14.4 | p3 | All | All |
| Operating System | Freebsd | Freebsd | 14.4 | p4 | All | All |
| Operating System | Freebsd | Freebsd | 14.4 | p5 | All | All |
| Operating System | Freebsd | Freebsd | 14.4 | p6 | All | All |
| Operating System | Freebsd | Freebsd | 14.4 | rc1 | All | All |
| Operating System | Freebsd | Freebsd | 15.0 | - | All | All |
| Operating System | Freebsd | Freebsd | 15.0 | p1 | All | All |
| Operating System | Freebsd | Freebsd | 15.0 | p10 | All | All |
| Operating System | Freebsd | Freebsd | 15.0 | p2 | All | All |
| Operating System | Freebsd | Freebsd | 15.0 | p3 | All | All |
| Operating System | Freebsd | Freebsd | 15.0 | p4 | All | All |
| Operating System | Freebsd | Freebsd | 15.0 | p5 | All | All |
| Operating System | Freebsd | Freebsd | 15.0 | p6 | All | All |
| Operating System | Freebsd | Freebsd | 15.0 | p7 | All | All |
| Operating System | Freebsd | Freebsd | 15.0 | p8 | All | All |
| Operating System | Freebsd | Freebsd | 15.0 | p9 | All | All |
| Operating System | Freebsd | Freebsd | 15.1 | - | All | All |
| Operating System | Freebsd | Freebsd | 15.1 | rc2 | All | All |
| Operating System | Freebsd | Freebsd | 15.1 | rc3-p1 | All | All |
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 | Vendor Advisory |
| 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.