SB20260912371 - Improper access control in Linux kernel iucv

Description

This security bulletin contains information about 1 vulnerability.

1) Improper access control (CVE-ID: CVE-2026-81003)

CWE-ID: CWE-284 - Improper Access Control

CVSSv4: 6.7 [CVSS:4.0/AV:L/AC:L/AT:N/PR:H/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]

The vulnerability allows a local user to inject data into existing AF_IUCV sockets and cause a denial of service.

The vulnerability exists due to improper ingress device validation in afiucv_hs_rcv() socket selection when processing a raw ETH_P_AF_IUCV frame received on a network device. A local user can send a crafted raw ETH_P_AF_IUCV frame through its loopback device to inject data into existing AF_IUCV sockets and cause a denial of service.

Exploitation requires CAP_NET_RAW in an unprivileged user and network namespace.

Remediation

Install update from vendor's website.

References

• https://git.kernel.org/stable/c/80230a18c164a4b5bbc048fe2768b219ac17bc5a
• https://git.kernel.org/stable/c/8e3763f1ccac3fc395f9af2b87114c023ced8a3f
• https://git.kernel.org/stable/c/a7f0130a091724e69827ab58e74777a88747e892
• https://git.kernel.org/stable/c/dfac2936b83be00035ae176f8252e1c1e1de9207