SB20260812415 - Use-after-free in Linux kernel net ppp driver
Published: August 12, 2026
Breakdown by Severity
- 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.
References
- https://git.kernel.org/stable/c/6866abf59976d273164a6624234d96a967280223
- https://git.kernel.org/stable/c/7e9fbd7f96bcde63a7c798fe16b38cedee7a1501
- https://git.kernel.org/stable/c/bed4caecd723693f750e13adbb2c42ca1249a3fd
- https://git.kernel.org/stable/c/e6493a4d1ee17595766165fa446d45b7e0c318d0
- https://git.kernel.org/stable/c/e9c238f6fe42fb1b4dba3a578277de32cb487937