CVE-2026-90179

Process hangs via recursive complain-mode hat locking

Published Sep 17, 2026 · Updated Sep 17, 2026

Deadlock in AppArmor in Linux Kernel allows local users to hang processes by requesting a missing hat in complain mode. In build_change_hat(), creation of a learning profile calls aa_new_learning_profile(), which reacquires the namespace mutex already held by change_hat(). The trigger requires a complain-mode profile and a nonexistent hat; the calling process becomes unkillable, and subsequent hat changes also hang.

CVSS severity5.5
Medium
EPSS probability0.21%
Next 30 days · Oct 19, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Deadlock in AppArmor in Linux Kernel allows local users to hang processes by requesting a missing hat in complain mode. In build_change_hat(), creation of a learning profile calls aa_new_learning_profile(), which reacquires the namespace mutex already held by change_hat(). The trigger requires a complain-mode profile and a nonexistent hat; the calling process becomes unkillable, and subsequent hat changes also hang.

The record

CVE
CVE-2026-90179
Published
Sep 17, 2026
Updated
Sep 17, 2026
Vendor
Linux Foundation
Product
Linux Kernel
Classifications
T1499.004
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Sep 17, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 17, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

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

  1. Affected versionversion=32e92764d6f8d251c1bca62be33793287b453a81 <072fb5aeec2eac7d445bf28c7119a1d6f6a2e333
  2. Affected versionversion=32e92764d6f8d251c1bca62be33793287b453a81 <4ec11f14d1d6fdda787d991b142537be7841d395
  3. Affected versionversion=5.10.261 <5.11
  4. Affected versionversion=5.15.212 <5.16
  5. Affected versionversion=5acb878db41328dae4d3249bc87b9ee4f290a663
  6. Affected versionversion=6.1.178 <6.2
  7. Affected versionversion=6.12.97 <6.13
  8. Affected versionversion=6.18.40 <6.18.52
  9. Affected versionversion=6446dbe02f4a3592bf062b4d12105927993086af
  10. Affected versionversion=65f95c1e7ce70bf339504e22473879e02026cfc4
  11. Affected versionversion=6.6.145 <6.7
  12. Affected versionversion=67ee65ec1a3eebdde76ccaa664d20dcf5b125a2f
  13. Affected versionversion=7.1.5 <7.2
  14. Affected versionversion=7.2
  15. Affected versionversion=862ae1fcc78aea9acab2ac87cccf6431f4682b8e
  16. Affected versionversion=9735e300a1c9259bfe4dc5ecdba472bb25574e8a
  17. Affected versionversion=b427061ca498309bf581bb6f8df4ffcfe4c772cd <00cce5e457cb690a3b3b3d334e76e71049ec8ae5

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

Linux Foundation · Linux Kernelversion=32e92764d6f8d251c1bca62be33793287b453a81 <072fb5aeec2eac7d445bf28c7119a1d6f6a2e333; version=32e92764d6f8d251c1bca62be33793287b453a81 <4ec11f14d1d6fdda787d991b142537be7841d395; version=5.10.261 <5.11; version=5.15.212 <5.16; version=5acb878db41328dae4d3249bc87b9ee4f290a663; version=6.1.178 <6.2; version=6.12.97 <6.13; version=6.18.40 <6.18.52; version=6446dbe02f4a3592bf062b4d12105927993086af; version=65f95c1e7ce70bf339504e22473879e02026cfc4; version=6.6.145 <6.7; version=67ee65ec1a3eebdde76ccaa664d20dcf5b125a2f; version=7.1.5 <7.2; version=7.2; version=862ae1fcc78aea9acab2ac87cccf6431f4682b8e; version=9735e300a1c9259bfe4dc5ecdba472bb25574e8a; version=b427061ca498309bf581bb6f8df4ffcfe4c772cd <00cce5e457cb690a3b3b3d334e76e71049ec8ae5

Published CVSS scores

5.5Amazon LinuxCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/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.

Activity data is delayed. The latest report is Sep 28, 2026.

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

No observations available

Sep 22, 2026Sep 28, 2026
Latest reporting daySep 28, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

T1499.004Application or System Exploitation

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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