CVE-2026-77488

Local information disclosure via integer underflow

Published Sep 8, 2026 · Updated Sep 9, 2026

Integer underflow in Microsoft SQL Server 2017, 2019, 2022, and 2025 allows local users to disclose information. Microsoft has not identified the affected component or explained how attacker-controlled data triggers the wraparound. Successful exploitation requires an authenticated local account and exposes data without modifying it or interrupting service.

CVSS severity5.5
Medium
EPSS probability0.30%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Integer underflow in Microsoft SQL Server 2017, 2019, 2022, and 2025 allows local users to disclose information. Microsoft has not identified the affected component or explained how attacker-controlled data triggers the wraparound. Successful exploitation requires an authenticated local account and exposes data without modifying it or interrupting service.

The record

CVE
CVE-2026-77488
Published
Sep 8, 2026
Updated
Sep 9, 2026
Vendor
Microsoft
Product
Microsoft SQL Server 2022
Classifications
CWE-191
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Sep 8, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 9, 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=16.0.0.0 <16.0.4275.2
  2. Affected versionversion=16.0.0 <16.0.1200.5

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

Microsoft · Microsoft SQL Server 2022version=16.0.0.0 <16.0.4275.2; version=16.0.0 <16.0.1200.5
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
Microsoft · Microsoft SQL Server 2025version=17.0.0.0 <17.0.4085.5; version=17.0.1050.2 <17.0.1135.8

Published CVSS scores

5.5MicrosoftCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/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-191Integer Underflow (Wrap or Wraparound)

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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