CVE Catalog

CVE-2026-64004

HighCVSS 7.8
Published: Updated: Translated: NVD NIST

Exploitation Probability (EPSS)

Low risk
0.13%

3th percentile - higher than 3% of all known CVEs

Summary

A vulnerability in the Linux kernel's locking mechanism for the .getsockopt function in AF_IUCV sockets was found. Missing proper locking allows a race condition between recvmsg() and getsockopt(SO_MSGSIZE), leading to a NULL pointer dereference and system crash.

Risk Assessment

Any AF_IUCV HIPER user can potentially crash the kernel, causing service disruption and loss of system availability.

Recommendation

Apply the kernel security patch immediately, which adds proper lock_sock()/release_sock() locking in the .getsockopt function for AF_IUCV.

Other vulnerabilities in Linux kernel

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Original NVD description (English source)

In the Linux kernel, the following vulnerability has been resolved: net/iucv: fix locking in .getsockopt Mirror iucv_sock_setsockopt() and wrap the whole switch in lock_sock()/release_sock(). The pre-existing SO_MSGLIMIT-only lock becomes redundant and is removed. Any AF_IUCV HIPER user can potentially crash the kernel by racing recvmsg() with getsockopt(SO_MSGSIZE): the SO_MSGSIZE arm dereferences iucv->hs_dev->mtu after iucv_sock_close() (called from the racing recvmsg()) has set hs_dev to NULL, producing a NULL pointer dereference oops.

Vulnerability data from NVD (NIST) · CISA KEV · EPSS