CVE-2026-97803

Local privilege escalation via kernel heap overflow

Published Oct 13, 2026 · Updated Oct 13, 2026

Heap overflow in the kernel of Microsoft Windows 11, version 26H1 allows local users to elevate privileges via unspecified vectors. The available Microsoft record does not identify the affected kernel routine, triggering input, or incorrect memory operation beyond the heap overflow classification. Exploitation requires an authorized local user; the resulting privilege level and additional configuration prerequisites are not disclosed in the retrieved record.

CVSS severityUnavailable
Unscored
EPSS probability0.31%
Next 30 days · Oct 19, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Heap overflow in the kernel of Microsoft Windows 11, version 26H1 allows local users to elevate privileges via unspecified vectors. The available Microsoft record does not identify the affected kernel routine, triggering input, or incorrect memory operation beyond the heap overflow classification. Exploitation requires an authorized local user; the resulting privilege level and additional configuration prerequisites are not disclosed in the retrieved record.

The record

CVE
CVE-2026-97803
Published
Oct 13, 2026
Updated
Oct 13, 2026
Vendor
Microsoft Corporation
Product
Windows 11, version 26H1
Classifications
CWE-122, T1068
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Oct 13, 2026CVE publishedPublication date reported by the CVE source.
  2. Oct 13, 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=10.0.28000.0 <10.0.28000.3231

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

Microsoft Corporation · Windows 11, version 26H1version=10.0.28000.0 <10.0.28000.3231

Published CVSS scores

No CVSS assessment is available in this record.

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.

Activity data is delayed. The latest report is Sep 28, 2026.

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

No observations available

Sep 22, 2026Sep 28, 2026
Latest reporting daySep 28, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-122Heap-based Buffer Overflow
T1068Exploitation for Privilege Escalation

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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