CVE-2026-45966

apparmor: fix NULL pointer dereference in __unix_needs_revalidation

MEDIUM
5.5
CVSS Score
Published: May 27, 2026 at 12:18 PM UTC
Updated: June 17, 2026 at 10:52 AM UTC
1 product affected across 1 vendorLinux Kernel

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Severity
MEDIUM5.5
Exploit prediction
EPSS 0.1%

Description

In the Linux kernel, the following vulnerability has been resolved: apparmor: fix NULL pointer dereference in __unix_needs_revalidation When receiving file descriptors via SCM_RIGHTS, both the socket pointer and the socket's sk pointer can be NULL during socket setup or teardown, causing NULL pointer dereferences in __unix_needs_revalidation(). This is a regression in AppArmor 5.0.0 (kernel 6.17+) where the new __unix_needs_revalidation() function was added without proper NULL checks. The crash manifests as: BUG: kernel NULL pointer dereference, address: 0x0000000000000018 RIP: aa_file_perm+0xb7/0x3b0 (or +0xbe/0x3b0, +0xc0/0x3e0) Call Trace: apparmor_file_receive+0x42/0x80 security_file_receive+0x2e/0x50 receive_fd+0x1d/0xf0 scm_detach_fds+0xad/0x1c0 The function dereferences sock->sk->sk_family without checking if either sock or sock->sk is NULL first. Add NULL checks for both sock and sock->sk before accessing sk_family.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

6.17 ≤ v < 6.18.146.17 ≤ v < 6.19.46.17 ≤ v < 7.06.19 ≤ v < 6.19.46.1788fec3526e84123997ecebd6bb6778eb4ce779b7
Vendor states this is fixed in e2938ad00b21340c0362562dfedd7cfec0554d67 (fixed)
Vendor states this is fixed in e85bc9101afc4202aa2269967ce9d3ffbecd0994 (fixed)
Vendor states this is fixed in fea017a7f6abe179decf575a2d8464c74edb3964 (fixed)
Vendor states this is fixed in 6.17 (unaffected)
Vendor states this is fixed in 6.18.14 (unaffected)
Vendor states this is fixed in 6.19.4 (unaffected)
Vendor states this is fixed in 7.0 (unaffected)

CVSS

Attack Vector
LOCAL
Complexity
LOW
Privileges
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
HIGH
Vector?

Quick Info

StatusANALYZED
CWE
CWE-476

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