What is CVE-2026-94520?

CVE-2026-94520 is a medium-severity vulnerability in Microsoft SQL Server 2017 For X64-Based Systems (Cu31), classified under Use of Externally-Controlled Format String. CVSS score: 4.9/10. Published 2026-10-13.

How severe is CVE-2026-94520?

Medium severity. CVSS v3 base score is 4.9 out of 10.

Vulnerability in Microsoft SQL Server 2017 For X64-Based Systems (Cu31)

CVE-2026-94520

Use of externally-controlled format string in SQL Server allows an authorized attacker to deny service over a network.

Published 2026-10-13 · last modified 2026-10-13.

CVSS v3 metric

CVSS v3 base score 4.9 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H.

EPSS exploit prediction

No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.

Affected products

Weakness classification (CWE)

CWE-134 — Use of Externally-Controlled Format String

References

msrc.microsoft.com/update-guide/vulnerability/CVE-2026-94520 (vendor-advisory, patch)

Frequently asked questions

What is CVE-2026-94520?: CVE-2026-94520 is a medium-severity vulnerability in Microsoft SQL Server 2017 For X64-Based Systems (Cu31), classified under Use of Externally-Controlled Format String. CVSS score: 4.9/10. Published 2026-10-13.
How severe is CVE-2026-94520?: Medium severity. CVSS v3 base score is 4.9 out of 10.