PT-2026-39119 · Linux · Linux Kernel

Published 2026-05-08 · Updated 2026-05-21 · CVE-2026-43458

Positive Technologies (AI Summary)

CVSS v3.1

7.8

High

Base vector

AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Name of the Vulnerable Software and Affected Versions Linux kernel (affected versions not specified)

Description A slab-use-after-free issue exists in the Linux kernel's caif serial line discipline. The problem occurs in the TX path when tty write room() is called, leading to a faulting access on tty->link->port within the pty write room() function. This happens because the reference to tty->link is not properly held during the lifetime of the caif serial line discipline.

Recommendations Update the Linux kernel to a version where the ldisc open() function acquires a kref on tty->link and the ser release() function drops it, ensuring the reference is also released on the ldisc open() error path.

Fix

Use After Free

Weakness Enumeration

CWE-416

Related Identifiers

CVE-2026-43458

Affected Products

Linux Kernel

References · 19

• https://git.kernel.org/stable/c/23a3ac2e2262a291498567418227b99e1f3606b1 · Patch
• https://ubuntu.com/security/CVE-2026-43458 · Vendor Advisory
• https://git.kernel.org/stable/c/ca2ceba983bb23ea0202c2882d963253416654a3 · Patch
• https://nvd.nist.gov/vuln/detail/CVE-2026-43458 · Security Note
• https://git.kernel.org/stable/c/8460187b4852fd00bd1c76394358053f3fa4d089 · Patch
• https://cve.org/CVERecord?id=CVE-2026-43458 · Security Note
• https://git.kernel.org/stable/c/97a0bb491cae39478c6225381f14e9ac67b7bba7 · Patch
• https://osv.dev/vulnerability/UBUNTU-CVE-2026-43458 · Vendor Advisory
• https://osv.dev/vulnerability/DEBIAN-CVE-2026-43458 · Vendor Advisory
• https://git.kernel.org/stable/c/35b58d3bc716ebb9ebd10fe1cac8c1177242511c · Patch
• https://git.kernel.org/stable/c/52135420e9f75853ea0c6cea7b736e3e98495f7d · Patch
• https://git.kernel.org/stable/c/288598d80a068a0e9281de35bcb4ce495f189e2a · Patch
• https://git.kernel.org/stable/c/27e43356d0defb9fc7fa25265219a3ffeb7b3e98 · Patch
• https://osv.dev/vulnerability/BELL-CVE-2026-43458 · Vendor Advisory
• https://security-tracker.debian.org/tracker/CVE-2026-43458 · Vendor Advisory