CVE-2026-23411

Local privilege escalation via AppArmor inode use-after-free

Published Apr 1, 2026 · Updated Apr 1, 2026

Use-after-free in AppArmor's apparmorfs in Linux Kernel branches from 4.13 allows local users to elevate privileges through a race. AppArmor releases an inode's i_private reference when removing its filesystem entry even though callbacks can access the data until inode eviction. Unprivileged access through user namespaces reaches the flaw; a successful race exposes kernel memory, grants elevated privileges, or enables container escape.

CVSS severity7.8
High
EPSS probability0.14%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Use-after-free in AppArmor's apparmorfs in Linux Kernel branches from 4.13 allows local users to elevate privileges through a race. AppArmor releases an inode's i_private reference when removing its filesystem entry even though callbacks can access the data until inode eviction. Unprivileged access through user namespaces reaches the flaw; a successful race exposes kernel memory, grants elevated privileges, or enables container escape.

The record

CVE
CVE-2026-23411
Published
Apr 1, 2026
Updated
Apr 1, 2026
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
CWE-362, T1068
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Apr 1, 2026CVE publishedPublication date reported by the CVE source.
  2. Apr 1, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=4.13
  2. Affected versionversion=c961ee5f21b202dea60b63eeef945730d92e46a6 <13bc2772414d68e94e273dea013181a986948ddf
  3. Affected versionversion=c961ee5f21b202dea60b63eeef945730d92e46a6 <2a732ed26fbd048e7925d227af8cf9ea43fb5cc9
  4. Affected versionversion=c961ee5f21b202dea60b63eeef945730d92e46a6 <8e135b8aee5a06c52a4347a5a6d51223c6f36ba3
  5. Affected versionversion=c961ee5f21b202dea60b63eeef945730d92e46a6 <ae10787d955fb255d381e0d5589451dd72c614b1
  6. Affected versionversion=c961ee5f21b202dea60b63eeef945730d92e46a6 <eecce026399917f6efa532c56bc7a3e9dd6ee68b

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linux Kernelversion=4.13; version=c961ee5f21b202dea60b63eeef945730d92e46a6 <13bc2772414d68e94e273dea013181a986948ddf; version=c961ee5f21b202dea60b63eeef945730d92e46a6 <2a732ed26fbd048e7925d227af8cf9ea43fb5cc9; version=c961ee5f21b202dea60b63eeef945730d92e46a6 <8e135b8aee5a06c52a4347a5a6d51223c6f36ba3; version=c961ee5f21b202dea60b63eeef945730d92e46a6 <ae10787d955fb255d381e0d5589451dd72c614b1; version=c961ee5f21b202dea60b63eeef945730d92e46a6 <eecce026399917f6efa532c56bc7a3e9dd6ee68b

Published CVSS scores

7.8kernel.orgCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-362Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')
T1068Exploitation for Privilege Escalation

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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