---
id: CVE-2026-89766
title: 'kernel: pidfd: hold exec_update_lock around namespace ioctl (CVE-2026-89766)'
summary: >-
  A flaw was found in the Linux kernel. A local attacker could exploit a race
  condition in the `pidfd` subsystem, specifically within the
  `PIDFD_GET_*_NAMESPACE` ioctls. This vulnerability occurs because the system
  does not properly hold a l…
severity: high
cvss: 7
cvssVector: 'CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H'
cvssSource: vendor
cwe: CWE-367
vendor: Red Hat
product: Red Hat Enterprise Linux 9
affected:
  - enterprise_linux 10
  - enterprise_linux 9
  - openshift_container_platform 4
published: '2026-09-11'
updated: '2026-09-21'
sourceUpdated: '2026-09-21T19:34:54+00:00'
source: CSAF
sourceUrl: 'https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89766.json'
references:
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89766.json
  - url: 'https://access.redhat.com/security/cve/CVE-2026-89766'
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2532287'
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-89766'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-89766'
  - url: >-
      https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-89766.mbox
  - url: 'https://git.kernel.org/stable/c/9688a46802939da28f00cb40e8129615d5d4af39'
  - url: 'https://git.kernel.org/stable/c/cf24ce48d60225fdbee68ed2058763a1fd172ff3'
  - url: 'https://git.kernel.org/stable/c/e89318aa8629969e86548b05e7c19283af3f0efb'
tags:
  - csaf
  - vex
  - red-hat
  - cve.org
epss: 0.00206
epssPercentile: 0.09458
ingestedAt: '2026-09-14T11:11:19.884Z'
---

## Overview

A flaw was found in the Linux kernel. A local attacker could exploit a race condition in the `pidfd` subsystem, specifically within the `PIDFD_GET_*_NAMESPACE` ioctls. This vulnerability occurs because the system does not properly hold a lock (`exec_update_lock`) during credential checks. This allows an attacker to bypass security restrictions and access sensitive namespace information after a target process has changed its privileges, leading to unauthorized information disclosure.

## Vendor advisories

- **Red Hat VEX** · Moderate · affected: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 9, Red Hat OpenShift Container Platform 4 · no fix planned: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 9, Red Hat OpenShift Container Platform 4 · updated 2026-09-21 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89766.json)

**kernel: pidfd: hold exec_update_lock around namespace ioctl** — rated Moderate by Red Hat. Released 2026-09-11, updated 2026-09-21.

Affected:

- Red Hat Enterprise Linux 10
- Red Hat Enterprise Linux 9
- Red Hat OpenShift Container Platform 4

No fix planned:

- Red Hat Enterprise Linux 10
- Red Hat Enterprise Linux 9
- Red Hat OpenShift Container Platform 4

Not affected:

- Red Hat Enterprise Linux 6
- Red Hat Enterprise Linux 7
- Red Hat Enterprise Linux 8
- Red Hat OpenShift Container Platform 4

## Remediation

Affected