SB20260812415 - Use-after-free in Linux kernel net ppp driver



SB20260812415 - Use-after-free in Linux kernel net ppp driver

Published: August 12, 2026

Security Bulletin ID SB20260812415
CSH Severity
Low
Patch available
YES
Number of vulnerabilities 1
Exploitation vector Local access
Highest impact Data manipulation

Breakdown by Severity

Low 100%
  • Low
  • Medium
  • High
  • Critical

Description

This security bulletin contains information about 1 vulnerability.


1) Use-after-free (CVE-ID: CVE-2026-68121)

CWE-ID: CWE-416 - Use After Free

CVSSv4: 5.8 [CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:N/VI:H/VA:H/SC:N/SI:N/SA:N]


The vulnerability allows a local user to cause memory corruption.

The vulnerability exists due to a use-after-free in pppoe_sendmsg() when handling a blocked send while a non-Ethernet port is added to an empty team device. A local user can trigger skb head reallocation and subsequent writes through a stale PPPoE header pointer to cause memory corruption.

The issue occurs because device header callbacks may reallocate the skb head and invalidate saved pointers into it.


Remediation

Install update from vendor's website.