Linux Kernel up to 7.0-rc3 apparmor privilege escalation

CVSS Meta Temp Score
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CTI Interest Score
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4.4$0-$5k0.00

Summaryinfo

A vulnerability classified as critical has been found in Linux Kernel up to 6.6.129/6.12.76/6.18.17/6.19.7/7.0-rc3. Affected by this issue is some unknown functionality of the component apparmor. This manipulation causes an unknown weakness. The identification of this vulnerability is CVE-2026-23405. There is no exploit available. It is recommended to upgrade the affected component.

Detailsinfo

A vulnerability classified as critical was found in Linux Kernel up to 6.6.129/6.12.76/6.18.17/6.19.7/7.0-rc3. Affected by this vulnerability is some unknown processing of the component apparmor. The impact remains unknown. The summary by CVE is:

In the Linux kernel, the following vulnerability has been resolved: apparmor: fix: limit the number of levels of policy namespaces Currently the number of policy namespaces is not bounded relying on the user namespace limit. However policy namespaces aren't strictly tied to user namespaces and it is possible to create them and nest them arbitrarily deep which can be used to exhaust system resource. Hard cap policy namespaces to the same depth as user namespaces.

It is possible to read the advisory at git.kernel.org. This vulnerability is known as CVE-2026-23405 since 01/13/2026. The exploitation appears to be difficult. The technical details are unknown and an exploit is not publicly available. The pricing for an exploit might be around USD $0-$5k at the moment (estimation calculated on 07/01/2026).

The vulnerability scanner Nessus provides a plugin with the ID 311108 (Ubuntu 20.04 LTS : Linux kernel (BlueField) vulnerabilities (USN-8224-1)), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 6.6.130, 6.12.77, 6.18.18, 6.19.8 or 7.0-rc4 eliminates this vulnerability. Applying the patch 3f8699b3ee0c04b4b9bc27b82cd89a40e81e1d2e/853ce31ca72097d23991a06876a2ccb5cb64b603/d42b2b6bb77ca40ee34ab74ad79305840b5f315d/7b6495ead2c611647f6b11441a852324e3eb8616/306039414932c80f8420695a24d4fe10c84ccfb2 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 databases at Tenable (311108), EUVD (EUVD-2026-17833) and CERT Bund (WID-SEC-2026-0950). Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

Affected

  • Google Container-Optimized OS
  • Debian Linux
  • Red Hat Enterprise Linux
  • Ubuntu Linux
  • SUSE Linux
  • Oracle Linux
  • SUSE openSUSE
  • RESF Rocky Linux
  • Microsoft Azure Linux
  • Open Source Linux Kernel

Productinfo

Type

Vendor

Name

Version

License

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 4.6
VulDB Meta Temp Score: 4.4

VulDB Base Score: 4.6
VulDB Temp Score: 4.4
VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv2info

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

Exploitinginfo

Class: Privilege escalation
CWE: Unknown
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Partially

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

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Nessus ID: 311108
Nessus Name: Ubuntu 20.04 LTS : Linux kernel (BlueField) vulnerabilities (USN-8224-1)

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Kernel 6.6.130/6.12.77/6.18.18/6.19.8/7.0-rc4
Patch: 3f8699b3ee0c04b4b9bc27b82cd89a40e81e1d2e/853ce31ca72097d23991a06876a2ccb5cb64b603/d42b2b6bb77ca40ee34ab74ad79305840b5f315d/7b6495ead2c611647f6b11441a852324e3eb8616/306039414932c80f8420695a24d4fe10c84ccfb2

Timelineinfo

01/13/2026 CVE reserved
04/01/2026 +77 days Advisory disclosed
04/01/2026 +0 days VulDB entry created
07/01/2026 +91 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2026-23405 (🔒)
GCVE (CVE): GCVE-0-2026-23405
GCVE (VulDB): GCVE-100-354619
EUVD: 🔒
CERT Bund: WID-SEC-2026-0950 - Linux Kernel: Mehrere Schwachstellen

Entryinfo

Created: 04/01/2026 11:25
Updated: 07/01/2026 14:50
Changes: 04/01/2026 11:25 (57), 04/01/2026 21:59 (7), 04/15/2026 07:02 (1), 04/19/2026 23:44 (1), 04/30/2026 17:41 (2), 05/04/2026 06:41 (1), 07/01/2026 14:50 (1)
Complete: 🔍
Cache ID: 216::103

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