CVE-2026-57973

Local kernel tampering via TOCTOU race

Published Jul 14, 2026 · Updated Jul 14, 2026

TOCTOU race condition in Microsoft Windows Subsystem for Linux before 2.7.10 allows local users to tamper with kernel-managed data. Microsoft identifies a kernel race between a security check and later use, but has not disclosed the affected function, object, or attacker-controlled operation. Successful exploitation requires existing local privileges and winning a high-complexity race; Microsoft reports disclosure and tampering without service interruption.

CVSS severity6.3
Medium
EPSS probability0.22%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

TOCTOU race condition in Microsoft Windows Subsystem for Linux before 2.7.10 allows local users to tamper with kernel-managed data. Microsoft identifies a kernel race between a security check and later use, but has not disclosed the affected function, object, or attacker-controlled operation. Successful exploitation requires existing local privileges and winning a high-complexity race; Microsoft reports disclosure and tampering without service interruption.

The record

CVE
CVE-2026-57973
Published
Jul 14, 2026
Updated
Jul 14, 2026
Vendor
Microsoft
Product
Windows Subsystem for Linux
Classifications
CWE-367
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Jul 14, 2026CVE publishedPublication date reported by the CVE source.
  2. Jul 14, 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=5.0.0.0 <2.7.10

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

Microsoft · Windows Subsystem for Linuxversion=5.0.0.0 <2.7.10

Published CVSS scores

6.3Microsoft CorporationCVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:N
4.7NIST NVDCVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:H/A:N

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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

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

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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