What is CVE-2026-77488?

CVE-2026-77488 is a medium-severity vulnerability in Microsoft SQL Server 2017 (Cu 31), classified under Integer Underflow. CVSS score: 5.5/10. Published 2026-09-08.

How severe is CVE-2026-77488?

Medium severity. CVSS v3 base score is 5.5 out of 10.

Integer overflow in Microsoft SQL Server 2017 (Cu 31)

CVE-2026-77488

Integer underflow (wrap or wraparound) in SQL Server allows an authorized attacker to disclose information locally.

Published 2026-09-08 · last modified 2026-09-15.

CVSS v3 metric

CVSS v3 base score 5.5 (Medium). Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N.

EPSS exploit prediction

EPSS: 0.004 (33.5th percentile), scored 2026-10-24.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 34th percentile — 33.5% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.004 · newest: 0.004 · change: 0.000

Affected products

Weakness classification (CWE)

CWE-191 — Integer Underflow

References

Microsoft SQL Server Information Disclosure Vulnerability (vendor-advisory, Patch, patch, Vendor Advisory)

Frequently asked questions

What is CVE-2026-77488?: CVE-2026-77488 is a medium-severity vulnerability in Microsoft SQL Server 2017 (Cu 31), classified under Integer Underflow. CVSS score: 5.5/10. Published 2026-09-08.
How severe is CVE-2026-77488?: Medium severity. CVSS v3 base score is 5.5 out of 10.