SB2026062585 - Improper access control in Linux kernel net ppp driver
Published: June 25, 2026
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 1 vulnerability.
1) Improper access control (CVE-ID: CVE-2026-53075)
CWE-ID: CWE-284 - Improper Access Control
CVSSv4: CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N/E:U/U:Clear
The vulnerability allows a local user to perform unauthorized PPP administrative operations in an inherited network namespace.
The vulnerability exists due to improper access control in unattached PPP administrative ioctl handling in drivers/net/ppp/ppp_generic.c when processing PPPIOCNEWUNIT, PPPIOCATTACH, or PPPIOCATTCHAN requests. A local user can create a new user namespace and issue crafted ioctl requests to perform unauthorized PPP administrative operations in an inherited network namespace.
Exploitation requires the ability to create a new user namespace with CLONE_NEWUSER.
Remediation
Install update from vendor's website.
References
- https://git.kernel.org/stable/c/1a8a51ce85075a56a743b6f142606dd2696a391c
- https://git.kernel.org/stable/c/2bb6379416fd19f44c3423a00bfd8626259f6067
- https://git.kernel.org/stable/c/3b2c2157dc2afc5c17cd7238afefca92f1ef330e
- https://git.kernel.org/stable/c/5013be175c7ffd8b39efbc3c9c4db5b10b85fea8
- https://git.kernel.org/stable/c/5080e188c914110034bbc569d5cfa2f06204681d
- https://git.kernel.org/stable/c/67e901e28d177ac9a9bed76d69ce3471e704a89e
- https://git.kernel.org/stable/c/954745d0223e7caec917c0b2d1a889ff56fa6e54
- https://git.kernel.org/stable/c/c9edd90c57ae23692fff6b049fdfa4572a9fd532