CVE-2026-49428
Received Received - Intake

Memory Corruption in FreeBSD Kernel

Publication date: 2026-08-19

Last updated on: 2026-08-19

Assigner: FreeBSD

Description
Certain system calls, such open(2) with the O_TRUNC flag set, and fspacectl(2), could incorrectly free memory in largepage objects. These operations are not permitted on largepage objects, but the implementation did not verify this. An unprivileged local user can abuse the bug to access freed kernel memory. This can be exploited to escalate privileges.

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Meta Information

Published
2026-08-19
Last Modified
2026-08-19
Generated
2026-08-19
AI Q&A
2026-08-19
EPSS Evaluated
N/A
NVD
CVE-2026-49428
EUVD
EUVD-2026-62255

Affected Vendors & Products

Showing 1 associated CPE
Vendor Product Version / Range
freebsd freebsd From 14 (inc) to 15 (inc)

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Exploitability

CWE
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KEV
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CWE ID Description
CWE-915 The product receives input from an upstream component that specifies multiple attributes, properties, or fields that are to be initialized or updated in an object, but it does not properly control which attributes can be modified.

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Executive Summary

This vulnerability involves certain system calls like open(2) with O_TRUNC or fspacectl(2) incorrectly freeing memory in largepage objects. These operations are not allowed on largepage objects, but the system fails to verify this. An unprivileged local user can exploit this to access freed kernel memory and escalate privileges.

Detection Guidance

Detecting this vulnerability requires checking if your FreeBSD system is running a vulnerable version. Use the command 'freebsd-version' to check your current version. If your system is running a version before the patched releases (stable/15, stable/14, or their respective release branches updated after June 30, 2026), it is likely vulnerable.

Impact Analysis

An unprivileged local attacker could exploit this flaw to access freed kernel memory, potentially leading to privilege escalation. This means an attacker could gain higher-level permissions on your system without proper authorization.

Mitigation Strategies

Immediately upgrade your FreeBSD system to a patched version (stable/15, stable/14, or their respective release branches updated after June 30, 2026). Use 'freebsd-update fetch install' or 'pkg update && pkg upgrade' to apply patches. After updating, reboot the system to ensure the changes take effect.

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