---
id: CVE-2026-31555
title: >-
  kernel: futex: Clear stale exiting pointer in futex_lock_pi() retry path
  (CVE-2026-31555)
summary: >-
  A flaw was found in the Linux kernel. A local user could exploit a race
  condition within the `futex_lock_pi()` retry path. This vulnerability occurs
  because a stale pointer to an exiting process is not cleared, leading to a
  kernel warning.…
severity: medium
cvss: 5.5
cvssVector: 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H'
cvssSource: vendor
cwe: CWE-825
vendor: Red Hat
product: Red Hat Enterprise Linux BaseOS (v. 9)
affected:
  - enterprise_linux 10
  - enterprise_linux 7
  - enterprise_linux 8
  - enterprise_linux 9
  - enterprise_linux_appstream_v_9
  - enterprise_linux_baseos_v_9
  - enterprise_linux_codeready_linux_builder_v_9
  - enterprise_linux_real_time_for_nfv_v_9
  - enterprise_linux_real_time_v_9
patched:
  - enterprise_linux_appstream_v_9
  - enterprise_linux_baseos_v_9
  - enterprise_linux_codeready_linux_builder_v_9
  - enterprise_linux_real_time_for_nfv_v_9
  - enterprise_linux_real_time_v_9
published: '2026-04-24'
updated: '2026-09-15'
sourceUpdated: '2026-09-15T23:44:33+00:00'
source: CSAF
sourceUrl: 'https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-31555.json'
references:
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-31555.json
  - url: 'https://access.redhat.com/security/cve/CVE-2026-31555'
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2461473'
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-31555'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-31555'
  - url: >-
      https://lore.kernel.org/linux-cve-announce/2026042456-CVE-2026-31555-ba94@gregkh/T
  - url: 'https://access.redhat.com/errata/RHSA-2026:51035'
  - url: 'https://git.kernel.org/stable/c/33095ae3bdde5e5c264d7e88a2f3e7703a26c7aa'
  - url: 'https://git.kernel.org/stable/c/e7824ec168d2ac883a213cd1f4d6cc0816002a85'
  - url: 'https://git.kernel.org/stable/c/5e8e06bf8909e79b4acd950cf578cfc2f10bbefa'
  - url: 'https://git.kernel.org/stable/c/de7c0c04ad868f2cee6671b11c0a6d20421af1da'
  - url: 'https://git.kernel.org/stable/c/7475dfad10a05a5bfadebf5f2499bd61b19ed293'
  - url: 'https://git.kernel.org/stable/c/92e47ad03e03dbb5515bdf06444bf6b1e147310d'
  - url: 'https://git.kernel.org/stable/c/71112e62807d1925dc3ae6188b11f8cfc85aec23'
  - url: 'https://git.kernel.org/stable/c/210d36d892de5195e6766c45519dfb1e65f3eb83'
tags:
  - csaf
  - vex
  - red-hat
  - cve.org
epss: 0.00171
epssPercentile: 0.05675
ingestedAt: '2026-09-08T15:33:26.990Z'
---

## Overview

A flaw was found in the Linux kernel. A local user could exploit a race condition within the `futex_lock_pi()` retry path. This vulnerability occurs because a stale pointer to an exiting process is not cleared, leading to a kernel warning. Successful exploitation of this flaw could result in a system crash, causing a Denial of Service (DoS).

## Vendor advisories

- **RHSA-2026:51035** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream (v. 9), Red Hat Enterprise Linux BaseOS (v. 9), Red Hat Enterprise Linux CodeReady Linux Builder (v. 9), Red Hat Enterprise Linux Real Time for NFV (v. 9), Red Hat Enterprise Linux Real Time (v. 9) · released 2026-08-06 · [advisory](https://access.redhat.com/errata/RHSA-2026:51035)
- **Red Hat VEX** · Moderate · affected: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 7, Red Hat Enterprise Linux 8, Red Hat Enterprise Linux 9 · no fix planned: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 7, Red Hat Enterprise Linux 8, Red Hat Enterprise Linux 9 · updated 2026-09-15 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-31555.json)

**kernel: futex: Clear stale exiting pointer in futex_lock_pi() retry path** — rated Moderate by Red Hat. Released 2026-04-24, updated 2026-09-15.

Affected:

- Red Hat Enterprise Linux 10
- Red Hat Enterprise Linux 7
- Red Hat Enterprise Linux 8
- Red Hat Enterprise Linux 9

Fixed:

- Red Hat Enterprise Linux AppStream (v. 9)
- Red Hat Enterprise Linux BaseOS (v. 9)
- Red Hat Enterprise Linux CodeReady Linux Builder (v. 9)
- Red Hat Enterprise Linux Real Time for NFV (v. 9)
- Red Hat Enterprise Linux Real Time (v. 9)

No fix planned:

- Red Hat Enterprise Linux 10
- Red Hat Enterprise Linux 7
- Red Hat Enterprise Linux 8
- Red Hat Enterprise Linux 9

Not affected:

- Red Hat Enterprise Linux 6

## Remediation

For details on how to apply this update, which includes the changes described in this advisory, refer to:

https://access.redhat.com/articles/11258

The system must be rebooted for this update to take effect.

Red Hat recommends treating all kernel errata as security-relevant. Given the kernel's fundamental role, any bug has a higher chance of impacting system security, even if that impact only becomes clear after a fix is published. Therefore, Red Hat prioritizes delivering fixes that improve our customers' overall security posture.

Because of this proactive approach, a patch may be associa… https://access.redhat.com/errata/RHSA-2026:51035