Improper access control in Linux kernel - CVE-2026-81003
Published: September 12, 2026
Vulnerability identifier: #VU149393
CSH Severity: Low
CVSS v4: 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]
CVE-ID: CVE-2026-81003
CWE-ID: CWE-284
Exploitation vector: Local access
Exploit availability:
No public exploit available
Vulnerability details
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.
Affected software
Linux kernel
How to mitigate CVE-2026-81003
Install security update from vendor's repository.