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CVE-2026-67638 Microsoft CVE debrief

CVE-2026-67638 is a high-severity heap-based buffer overflow vulnerability in SQL Server 2025. An authorized attacker can exploit this vulnerability to execute code over a network. Defenders should prioritize verifying exposure, applying patches, and restricting network access to prevent exploitation. This vulnerability has a CVSS score of 8.8 and is considered HIGH severity. The CVE record and NVD entry provide details on the vulnerability, and defenders should review these sources for more information.

Vendor
Microsoft
Product
SQL Server 2025
CVSS
HIGH 8.8
CISA KEV
Not listed in stored evidence
Original CVE published
2026-09-08
Original CVE updated
2026-09-15
Advisory published
2026-09-08
Advisory updated
2026-09-15

Who should care

Defenders responsible for SQL Server 2025 deployments should assess exposure and prioritize patching. This includes operators, platform administrators, vulnerability management teams, and security teams. Defenders should review the CVE record and NVD entry for more information on the vulnerability and its potential impact.

Why it matters

CVE-2026-67638 is a high-severity vulnerability in SQL Server 2025 that allows authorized attackers to execute code over a network. Defenders should prioritize verifying exposure, applying patches, and restricting network access to prevent exploitation.

  • Verify exposure and apply patches to prevent code execution
  • Restrict network access to SQL Server to reduce attack surface
  • Monitor for suspicious activity to detect potential exploitation

Technical summary

CVE-2026-67638 is a heap-based buffer overflow vulnerability in SQL Server 2025 that allows an authorized attacker to execute code over a network. The vulnerability has a CVSS score of 8.8 and is considered HIGH severity. Defenders should prioritize verifying exposure and applying patches to prevent exploitation. The vulnerability is related to the SQL Server 2025 product and has been documented in the CVE record and NVD entry.

Defensive priority

Defenders should prioritize verifying exposure and applying patches for SQL Server 2025.

Recommended defensive actions

  • Verify SQL Server 2025 versions and apply patches if necessary
  • Review network exposure and restrict access to SQL Server
  • Monitor for suspicious activity and implement compensating controls

Evidence notes

The CVE record and NVD entry provide details on the heap-based buffer overflow vulnerability in SQL Server 2025. The vulnerability allows an authorized attacker to execute code over a network. Defenders should verify exposure and apply patches to prevent exploitation. The CVE record was published on 2026-09-08T18:18:24.023Z and has not been modified since then. The NVD entry provides additional information on the vulnerability, including its CVSS score and severity.

Sources and references

Verified primary and authoritative sources

  • CVE-2026-67638 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-67638

    CVE Program - Official CVE Program record with source-provided CVE metadata.

  • CVE-2026-67638 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-67638

    NIST National Vulnerability Database - Official NIST NVD detail page and source-specific vulnerability assessment.

Supplemental references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.