CVE-2026-62840 — Linux Kernel Elevation of Privilege Vulnerability

Executive Summary

Time-of-check time-of-use (toctou) race condition in Linux Kernel allows an authorized attacker to elevate privileges locally.

Overview

7

CVSS HIGH

Critical

MS Severity

Not Exploited

MS Exploit Status

Less Likely

MS Exploit Likelihood

Category Elevation of Privilege

Weakness CWE-367: Time-of-check Time-of-use (TOCTOU) Race Condition

Released Oct 13 2026

Last Updated Oct 13 2026

Publicly Disclosed No

CISA KEV Not Listed

Known Exploits None Known

CVSS Vector

ATTACK VECTOR

Local

ATTACK COMPLEXITY

High

PRIVILEGES REQUIRED

Low

USER INTERACTION

None

SCOPE

Unchanged

CONFIDENTIALITY

High

INTEGRITY

High

AVAILABILITY

High

EXPLOIT CODE MATURITY

Unproven

REMEDIATION LEVEL

Official Fix

REPORT CONFIDENCE

Confirmed

Temporal Score: 6.1

EPSS Score

No EPSS score available for this CVE.

View on FIRST.org

Affected Products

1 affected product

Product	KB Article	Severity	Impact	Restart Required
Linux 3P (Third Party) Distros	`Release Notes (Security Update)`	Critical	Elevation of Privilege	Maybe

Patches

1 patch

Article	Type	Restart
`Release Notes`	Security Update	Maybe

Exploits & PoC

No public exploit or PoC has been linked for this CVE yet. When available, references are sourced from public repositories and may be unverified or non-functional — review carefully before use.

Detection Rules

No public Sigma or Nuclei detection rule has been mapped to this CVE yet. Coverage is concentrated on exploited / high-profile vulnerabilities; check SigmaHQ for updates.

Acknowledgments

Jonathan Guerin with Microsoft
Vincent Yin with Microsoft

References

MSRC Advisory MITRE NVD