CVE-2026-46104 selinux: use sk blob accessor in socket permission helpers

Medium 5.5 Published Updated

Incorrect SELinux socket blob access in stacked LSM configurations may bypass security checks by reading invalid data.

Exploited in the wild
Not known
Login needed
Any signed-in user
Attackable
Local or same network only
Victim action needed
Not needed
Fix
Available

What is CVE-2026-46104?

CVE-2026-46104 is a medium-severity vulnerability in Linux kernel, published on 28 May 2026. It can only be exploited from the same machine or local network, with no action from the victim.

Official description

In the Linux kernel, the following vulnerability has been resolved:

selinux: use sk blob accessor in socket permission helpers

SELinux socket state lives in the composite LSM socket blob.

sock_has_perm() and nlmsg_sock_has_extended_perms() currently dereference sk->sk_security directly, which assumes the SELinux socket blob is at offset zero.

In stacked configurations that assumption does not hold. If another LSM allocates socket blob storage before SELinux, these helpers may read the wrong blob and feed invalid SID and class values into AVC checks.

Use selinux_sock() instead of accessing sk->sk_security directly.

Which versions are affected by CVE-2026-46104?

It affects 1 product.

Products include Linux kernel.

How do I fix CVE-2026-46104?

Apply the vendor's patch.

Is CVE-2026-46104 being exploited?

There is no known exploitation of CVE-2026-46104 in the wild and no public exploit code.

All Linux kernel vulnerabilities

Sources

Also known as BELL-CVE-2026-46104, DEBIAN-CVE-2026-46104, GHSA-h7hm-vjhc-hcgc, UBUNTU-CVE-2026-46104.

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