CVE-2026-78442Network attack vector

Remote code execution via invalid TDS lengths

Published Sep 8, 2026 · Updated Sep 10, 2026

Heap-based buffer overflow in Windows OLE DB in Microsoft SQL Server 2017 and 2019 allows remote attackers to execute code. SQL Connectivity accepts malformed TDS and Binary XML records containing invalid length values without sufficient validation, causing an out-of-bounds heap write. Exploitation requires crafted network input and user interaction, and the affected component is limited to Windows x64 deployments.

CVSS severity8.8
High
EPSS probability0.56%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Heap-based buffer overflow in Windows OLE DB in Microsoft SQL Server 2017 and 2019 allows remote attackers to execute code. SQL Connectivity accepts malformed TDS and Binary XML records containing invalid length values without sufficient validation, causing an out-of-bounds heap write. Exploitation requires crafted network input and user interaction, and the affected component is limited to Windows x64 deployments.

The record

CVE
CVE-2026-78442
Published
Sep 8, 2026
Updated
Sep 10, 2026
Vendor
Microsoft
Product
Microsoft SQL Server 2019
Classifications
CWE-122, T1203
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Sep 8, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 10, 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=15.0.0.0 <15.0.4490.9
  2. Affected versionversion=15.0.0 <15.0.2190.7

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Microsoft · Microsoft SQL Server 2019version=15.0.0.0 <15.0.4490.9; version=15.0.0 <15.0.2190.7
Microsoft · Microsoft SQL Server 2017version=14.0.0 <14.0.2130.4; version=14.0.0 <14.0.3550.4

Published CVSS scores

8.8MicrosoftCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

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)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-122Heap-based Buffer Overflow
T1203Exploitation for Client Execution

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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