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CVE-2026-94520 Microsoft CVE debrief

Microsoft SQL Server Denial of Service Vulnerability allows an authorized attacker to deny service over a network via use of externally-controlled format string. This vulnerability impacts SQL Server deployments, potentially allowing attackers to disrupt service. Defenders should assess exposure and prioritize patching to mitigate potential denial of service attempts. The vulnerability's externally-controlled format string allows attackers to manipulate SQL Server, leading to service disruption.

Vendor
Microsoft
Product
Microsoft SQL Server 2017 (GDR)
CVSS
MEDIUM 4.9
CISA KEV
Not listed in stored evidence
Original CVE published
2026-10-13
Original CVE updated
2026-10-14
Advisory published
2026-10-13
Advisory updated
2026-10-14

Who should care

SQL Server administrators and defenders should assess exposure and prioritize patching to mitigate potential denial of service attempts. This vulnerability impacts SQL Server deployments, potentially allowing attackers to disrupt service. Defenders should verify exposure, prioritize patching, and monitor for potential denial of service attempts. SQL Server administrators and defenders should review compensating and

Why it matters

CVE-2026-94520 allows an authorized attacker to deny service over a network via use of externally-controlled format string in SQL Server. Defenders should verify exposure, prioritize patching, and monitor for potential denial of service attempts.

  • Denial of service attempts may occur
  • Verify exposure and apply patches
  • Monitor for potential attacks on SQL Server deployments

Technical summary

The vulnerability allows an authorized attacker to deny service over a network via use of externally-controlled format string in SQL Server. This impacts SQL Server deployments, potentially disrupting service. The externally-controlled format string vulnerability enables attackers to manipulate SQL Server, leading to service disruption. Defenders should prioritize verifying exposure in SQL Server deployments and applying vendor patches.

Defensive priority

Defenders should prioritize verifying exposure in SQL Server deployments and applying vendor patches.

Recommended defensive actions

  • Verify SQL Server deployments for exposure
  • Apply vendor patches
  • Monitor for potential denial of service attempts

Evidence notes

The CVE record and NVD entry provide details on the vulnerability. Vendor advisory and patch information is available. The vulnerability affects SQL Server, allowing an authorized attacker to deny service via externally-controlled format string. Defenders should verify exposure, prioritize patching, and monitor for potential denial of service attempts. The CVE Program record and NVD detail page offer source-provided metadata and vulnerability assessments.

Sources and references

Verified primary and authoritative sources

  • CVE-2026-94520 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-94520

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

  • CVE-2026-94520 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-94520

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

Supplemental references

  • Microsoft SQL Server Denial of Service Vulnerability

    Unverified legacy reference

    URL: https://raw.githubusercontent.com/CVEProject/cvelistV5/main/cves/2026/94xxx/CVE-2026-94520.json

    cve_program_cvelist_v5

  • Source reference

    Unverified legacy reference

    URL: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-94520

    Supplemental source - vendor-advisory, patch

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.