CVE-2026-90246

Memory disclosure and hang via wrapped tag count

Published Sep 17, 2026 · Updated Sep 18, 2026

Out-of-bounds read in Linux AppArmor 7.0 through 7.2.5 allows local users to crash or hang the kernel via a crafted policy blob. The verify_tags() check adds an unbounded u32 tag count to its index in u32, allowing wraparound to bypass the sets.table[] boundary. With unprivileged_userns_apparmor_policy=1, a task in a matched-level nested namespace can reach policy loading, exposing kernel memory or causing an oops or nonterminating loop.

CVSS severity7.1
High
EPSS probability0.17%
Next 30 days · Oct 19, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Out-of-bounds read in Linux AppArmor 7.0 through 7.2.5 allows local users to crash or hang the kernel via a crafted policy blob. The verify_tags() check adds an unbounded u32 tag count to its index in u32, allowing wraparound to bypass the sets.table[] boundary. With unprivileged_userns_apparmor_policy=1, a task in a matched-level nested namespace can reach policy loading, exposing kernel memory or causing an oops or nonterminating loop.

The record

CVE
CVE-2026-90246
Published
Sep 17, 2026
Updated
Sep 18, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
T1499
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Sep 17, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 18, 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=3d28e2397af7a89ac3de33c686ed404cda59b5d5 <465946d3c560c0137e6a180ba054dddc4d049f5a
  2. Affected versionversion=3d28e2397af7a89ac3de33c686ed404cda59b5d5 <ef79a405f83993f0fda5efde371d98433f7d7a47
  3. Affected versionversion=7.0

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=3d28e2397af7a89ac3de33c686ed404cda59b5d5 <465946d3c560c0137e6a180ba054dddc4d049f5a; version=3d28e2397af7a89ac3de33c686ed404cda59b5d5 <ef79a405f83993f0fda5efde371d98433f7d7a47; version=7.0

Published CVSS scores

7.1Linux CNACVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/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

T1499Endpoint Denial of Service

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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