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Used in attacks· fix by 2026-05-157.8High

Linux Kernel

CVE-2026-31431

Linux Kernel contains an incorrect resource transfer between spheres vulnerability that could allow for privilege escalation.

What this means for your business

  • It affects Linux Kernel. It matters if your company, or a supplier that handles your data, runs it.
  • Attackers are already using it. CISA added it to its list of flaws used in real attacks on 1 May 2026.
  • An attacker can use it only with access to the machine itself, with an ordinary user login, and without anyone at your company clicking anything.
  • FIRST's prediction model gives it a 100% chance of attack attempts being seen in the next 30 days, ranking above 99% of all known flaws.

What to do

  1. 1Check whether your company or your suppliers run Linux Kernel, and which version. The affected versions are listed further down this page.
  2. 2If you do, apply the vendor's fix. A patch or vendor advisory has been published.
  3. 3Treat it as urgent. US federal agencies must fix it by 15 May 2026. That deadline does not apply to private companies, but it shows how seriously CISA takes it.
  4. 4Because attackers have used it, check the affected systems for signs of a break-in, not only for the update.

Not sure if your company is exposed?

Fastnexa’s certified penetration testers can check whether attackers could use this flaw, or others like it, against your websites, apps and network. The full test is free for our first 10 founding clients until 31 December 2026.

Check if you’re exposedBook a call

Required action

"Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.

CISA’s wording, unedited.

Scoring

CVSS
7.8 (v3.1)
Vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Weakness
CWE-669
Assigned by
416baaa9-dc9f-4396-8d5f-8c081fb06d67

Dates

Published
2026-05-01
Last modified
2026-09-08
Added to KEV
2026-05-01
Remediation due
2026-05-15
Sources
CISA KEV, NVD

Affected products

  • Linux Linux Kernel4.14 - 5.10.254, 5.11 - 5.15.204, 5.16 - 6.1.170, 6.2 - 6.6.137, 6.7 - 6.12.85, 6.13 - 6.18.22, 6.19 - 6.19.12, 7.0
  • Redhat Openshift Container Platform4.12 - 4.12.89, 4.13 - 4.13.66, 4.14 - 4.14.65, 4.15 - 4.15.64, 4.16 - 4.16.61, 4.17 - 4.17.53, 4.18 - 4.18.40, 4.19 - 4.19.30, 4.20 - 4.20.21, 4.21 - 4.21.14, 4.0
  • Redhat Enterprise Linux8.0, 9.0, 10.0
  • Redhat Enterprise Linux Aus8.4, 8.6
  • Redhat Enterprise Linux Eus8.4, 9.4, 9.6, 10.0
  • Redhat Enterprise Linux Tus8.6, 8.8
  • Redhat Enterprise Linux Update Services For Sap Solutions8.6, 8.8, 9.0, 9.2
  • Amazon Amazon Linuxall versions
  • Canonical Ubuntu Linuxall versions, 14.04, 16.04, 18.04, 20.04, 22.04, 24.04, 25.10
  • Debian Debian Linux11.0, 12.0, 13.0
  • Opensuse Leap15.3, 15.4, 15.5, 15.6
  • Suse Caas Platform4.0

As listed in the NVD configuration data. Not a statement about your estate.

Coverage

References