CVE-2026-47331

Use-after-free in Ubuntu Linux AppArmor notification handling

Published May 28, 2026 CVSS 3.1 · 7.8 High EPSS < 1% KEV · Not listed
Description
Ubuntu Linux 6.8 contains AppArmor SAUCE patches which fail to acquire a lock when modifying a linked list. An unprivileged local user could trigger the race condition that can lead to a use-after-free (UAF) and, theoretically, arbitrary code execution.

Analysis

AI-generated

Technical impact

Ubuntu Linux kernel 6.8 contains a race condition in the AppArmor SAUCE notification handling code. When the code modifies a linked list it fails to acquire the necessary lock, allowing an unprivileged local user to trigger a use‑after‑free. If exploited, the attacker could potentially execute arbitrary code with the privileges of the affected process, undermining confidentiality, integrity, and availability of the system.

Affected Systems

The vulnerability is present in Canonical’s Ubuntu Linux distribution, specifically in the 6.8 kernel series. Users of this kernel, especially those running unprivileged local accounts, are susceptible until the patch is applied.

Risk and Exploitability

The CVSS score is 7.8, indicating a high severity. The EPSS score is not available, so the likelihood of opportunistic exploitation cannot be precisely quantified, but the vulnerability is not currently listed in the CISA KEV catalogue. Because the attack requires local execution, a compromised or malicious local user can trigger the race condition; the lack of a proper lock on the linked list provides the necessary window for the use‑after‑free.

Remediation

No solution or workaround provided in the CVE record.

OpenCVE Recommended Actions

  • Update the kernel to a version that includes the AppArmor SAUCE fixes, such as the latest Ubuntu 6.8 patch release.
  • If a kernel update is not yet available, consider disabling SAUCE or removing the affected notification handler via kernel module removal or disabling AppArmor SAUCE through sysctl to reduce the attack surface.
  • Audit and restrict local user privileges to minimize the ability to trigger notifications, enforce least‑privilege practices, and monitor logs for anomalous AppArmor activity.

Generated by OpenCVE AI on May 28, 2026 at 20:26 UTC.

Tracking

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Advisories

Source ID Title
Ubuntu USN Ubuntu USN USN-8373-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-8440-1 Linux kernel (Azure) vulnerabilities
Ubuntu USN Ubuntu USN USN-8497-1 Linux kernel (Low Latency) vulnerabilities
Ubuntu USN Ubuntu USN USN-8499-1 Linux kernel (Xilinx) vulnerabilities
Ubuntu USN Ubuntu USN USN-8393-1 Linux kernel (Azure FIPS) vulnerabilities
History
Type Values Removed Values Added
CPEs cpe:2.3:o:canonical:ubuntu_linux:24.04:*:*:*:*:*:*:*
cpe:2.3:o:canonical:ubuntu_linux:25.10:*:*:*:*:*:*:*
cpe:2.3:o:canonical:ubuntu_linux:26.04:*:*:*:*:*:*:*
Type Values Removed Values Added
First Time appeared Canonical
Canonical ubuntu Linux
Vendors & Products Canonical
Canonical ubuntu Linux
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}

Type Values Removed Values Added
Description Ubuntu Linux 6.8 contains AppArmor SAUCE patches which fail to acquire a lock when modifying a linked list. An unprivileged local user could trigger the race condition that can lead to a use-after-free (UAF) and, theoretically, arbitrary code execution.
Title Use-after-free in Ubuntu Linux AppArmor notification handling
Weaknesses CWE-416
References
Metrics cvssV3_1

{'score': 7.8, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
canonical
Published
Updated
May 29, 2026, 3:55 AM
Reserved
May 19, 2026, 10:37 AM
Status
Analyzed
Published
May 28, 2026, 7:16 PM
Modified
Oct 26, 2026, 1:10 PM