CVE-2026-49416

Integer overflow in vt(4) CONS_HISTORY ioctl

Published Jun 27, 2026 CVSS 3.1 · 7.8 High EPSS < 1% KEV · Not listed
Description
The CONS_HISTORY ioctl handler did not adequately validate the requested history size. A large value caused an integer overflow in the buffer size calculation, resulting in a heap allocation smaller than expected. Subsequent initialization of the buffer wrote beyond the end of the allocation.

An unprivileged local user with access to a vt(4) device can trigger an out-of-bounds write in the kernel, potentially escalating privileges.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

No advisories available
History
Type Values Removed Values Added
Metrics cvssV3_1

{'score': 7.8, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H'}

ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}

Type Values Removed Values Added
First Time appeared Freebsd
Freebsd freebsd
Vendors & Products Freebsd
Freebsd freebsd
Type Values Removed Values Added
Description The CONS_HISTORY ioctl handler did not adequately validate the requested history size. A large value caused an integer overflow in the buffer size calculation, resulting in a heap allocation smaller than expected. Subsequent initialization of the buffer wrote beyond the end of the allocation. An unprivileged local user with access to a vt(4) device can trigger an out-of-bounds write in the kernel, potentially escalating privileges.
Title Integer overflow in vt(4) CONS_HISTORY ioctl
Weaknesses CWE-190
References
Weaknesses

Sources

Status
PUBLISHED
Assigner
freebsd
Published
Updated
Jun 30, 2026, 3:55 AM
Reserved
May 29, 2026, 8:24 PM
Status
Analyzed
Published
Jun 27, 2026, 10:16 AM
Modified
Jul 1, 2026, 2:04 PM