CVE-2026-5398: Kernel use-after-free bug in the TIOCNOTTY handler

Published Apr 22, 2026
·
Updated

The implementation of TIOCNOTTY failed to clear a back-pointer from the structure representing the controlling terminal to the calling process' session. If the invoking process then exits, the terminal structure may end up containing a pointer to freed memory.

A malicious process can abuse the dangling pointer to grant itself root privileges.

Affected Software

34 affected components
Linux Linux kernel
FreeBSD FreeBSD=13.5
FreeBSD FreeBSD=13.5-beta3
FreeBSD FreeBSD=13.5-p1
FreeBSD FreeBSD=13.5-p10
FreeBSD FreeBSD=13.5-p11
FreeBSD FreeBSD=13.5-p2
FreeBSD FreeBSD=13.5-p3
FreeBSD FreeBSD=13.5-p4
FreeBSD FreeBSD=13.5-p5
FreeBSD FreeBSD=13.5-p6
FreeBSD FreeBSD=13.5-p7
FreeBSD FreeBSD=13.5-p8
FreeBSD FreeBSD=13.5-p9
FreeBSD FreeBSD=14.3
FreeBSD FreeBSD=14.3-p1
FreeBSD FreeBSD=14.3-p10
FreeBSD FreeBSD=14.3-p2
FreeBSD FreeBSD=14.3-p3
FreeBSD FreeBSD=14.3-p4
FreeBSD FreeBSD=14.3-p5
FreeBSD FreeBSD=14.3-p6
FreeBSD FreeBSD=14.3-p7
FreeBSD FreeBSD=14.3-p8
FreeBSD FreeBSD=14.3-p9
FreeBSD FreeBSD=14.4
FreeBSD FreeBSD=14.4-p1
FreeBSD FreeBSD=14.4-rc1
FreeBSD FreeBSD=15.0
FreeBSD FreeBSD=15.0-p1
FreeBSD FreeBSD=15.0-p2
FreeBSD FreeBSD=15.0-p3
FreeBSD FreeBSD=15.0-p4
FreeBSD FreeBSD=15.0-p5

Event History

Apr 22, 2026
CVE Published
via MITRE·02:23 AM
Data Sourced
via MITRE·02:23 AM
DescriptionWeakness
Data Sourced
via NVD·03:16 AM
DescriptionSeverityWeaknessAffected Software

Frequently Asked Questions

1

What is the severity of CVE-2026-5398?

CVE-2026-5398 is classified as a high severity vulnerability due to its potential to allow arbitrary code execution.

2

How do I fix CVE-2026-5398?

To fix CVE-2026-5398, you should update to the latest version of the Linux kernel that addresses this vulnerability.

3

What systems are affected by CVE-2026-5398?

CVE-2026-5398 affects various versions of the Linux kernel where the TIOCNOTTY handler implementation is present.

4

What can happen if CVE-2026-5398 is exploited?

If exploited, CVE-2026-5398 can lead to a use-after-free condition, potentially allowing an attacker to execute arbitrary code.

5

Is there a workaround for CVE-2026-5398 if I cannot update?

There is no officially recommended workaround for CVE-2026-5398, so updating the kernel is the best course of action.

Contact

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