Memory Access Vulnerability in FreeBSD Kernel Components
CVE-2026-49427

8.8HIGH

Key Information:

Vendor

FreeBSD

Status
FreeBSD
Vendor
CVE Published:
19 August 2026

What is CVE-2026-49427?

This vulnerability in the FreeBSD kernel affects largepage shared memory objects, where pages are not wired explicitly. When utilizing the sendfile() function with the SF_NOCACHE flag, the underlying pages are freed post-transmission despite ongoing references from existing mappings. This flaw allows unprivileged local users to exploit the system, granting them the ability to access freed kernel memory, which may lead to unauthorized privilege escalation.

Affected Version(s)

FreeBSD 15.1-RELEASE

FreeBSD 15.0-RELEASE

FreeBSD 14.4-RELEASE

References

https://security.freebsd.org/advisories/FreeBSD-SA-26:44....
vendor-advisory

CVSS V3.1

Score:
8.8
Severity:
HIGH
Confidentiality:
High
Integrity:
High
Availability:
High
Attack Vector:
Network
Attack Complexity:
Low
Privileges Required:
Low
User Interaction:
None
Scope:
Unchanged

Timeline

  • Vulnerability published

  • Vulnerability Reserved

Credit

Chris Jarrett-Davies of the OpenAI Codex Security Team
.