Linux Kernel up to 6.18.13/6.19.3 apparmor __unix_needs_revalidation null pointer dereference

CVSS Meta Temp Score
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CTI Interest Score
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5.0$0-$5k0.00

Summaryinfo

A vulnerability has been found in Linux Kernel up to 6.18.13/6.19.3 and classified as critical. The affected element is the function __unix_needs_revalidation of the component apparmor. This manipulation causes null pointer dereference. The identification of this vulnerability is CVE-2026-45966. There is no exploit available. The affected component should be upgraded.

Detailsinfo

A vulnerability classified as critical was found in Linux Kernel up to 6.18.13/6.19.3. Affected by this vulnerability is the function __unix_needs_revalidation of the component apparmor. The manipulation with an unknown input leads to a null pointer dereference vulnerability. The CWE definition for the vulnerability is CWE-476. A NULL pointer dereference occurs when the application dereferences a pointer that it expects to be valid, but is NULL, typically causing a crash or exit. As an impact it is known to affect availability. The summary by CVE is:

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.

The advisory is shared at git.kernel.org. This vulnerability is known as CVE-2026-45966 since 05/13/2026. The exploitation appears to be difficult. Technical details are known, but no exploit is available.

The vulnerability scanner Nessus provides a plugin with the ID 325425 (Ubuntu 24.04 LTS : Linux kernel (NVIDIA) vulnerabilities (USN-8508-1)), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 6.18.14 or 6.19.4 eliminates this vulnerability. Applying the patch fea017a7f6abe179decf575a2d8464c74edb3964/e85bc9101afc4202aa2269967ce9d3ffbecd0994/e2938ad00b21340c0362562dfedd7cfec0554d67 is able to eliminate this problem. The bugfix is ready for download at git.kernel.org. The best possible mitigation is suggested to be upgrading to the latest version.

The vulnerability is also documented in the vulnerability database at Tenable (325425). If you want to get the best quality for vulnerability data then you always have to consider VulDB.

Productinfo

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CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 5.1
VulDB Meta Temp Score: 5.0

VulDB Base Score: 4.8
VulDB Temp Score: 4.6
VulDB Vector: 🔒
VulDB Reliability: 🔍

NVD Base Score: 5.5
NVD Vector: 🔒

CVSSv2info

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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Null pointer dereference
CWE: CWE-476 / CWE-404
CAPEC: 🔒
ATT&CK: 🔒

Physical: Partially
Local: Yes
Remote: Partially

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

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Nessus ID: 325425
Nessus Name: Ubuntu 24.04 LTS : Linux kernel (NVIDIA) vulnerabilities (USN-8508-1)

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Kernel 6.18.14/6.19.4
Patch: fea017a7f6abe179decf575a2d8464c74edb3964/e85bc9101afc4202aa2269967ce9d3ffbecd0994/e2938ad00b21340c0362562dfedd7cfec0554d67

Timelineinfo

05/13/2026 CVE reserved
05/27/2026 +14 days Advisory disclosed
05/27/2026 +0 days VulDB entry created
07/08/2026 +42 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2026-45966 (🔒)
GCVE (CVE): GCVE-0-2026-45966
GCVE (VulDB): GCVE-100-366229

Entryinfo

Created: 05/27/2026 17:17
Updated: 07/08/2026 13:17
Changes: 05/27/2026 17:17 (59), 06/16/2026 09:01 (11), 07/08/2026 13:17 (2)
Complete: 🔍
Cache ID: 216::103

If you want to get the best quality for vulnerability data then you always have to consider VulDB.

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