CVE intelligence

CVE-2026-17084

Vulnerability intelligence

Published Aug 18, 2026Sources checked Oct 28, 2026

6.0MEDIUMCVSS out of 10

What this means

Review the available evidence

CVE-2026-17084 and is rated Medium severity with a CVSS score of 6.0. It is not in the current CISA KEV record we collected. That does not prove exploitation has not occurred.

What to do next

Remediation and response

Microsoft Security Response Center guidance

Vendor revision: Oct 7, 2026

Release Notes

Vendor-listed releases

3.12.15-1

CISA KEVNot listedBased on the latest collected catalog

EPSS0.7%Estimated 30-day exploitation probability

Ransomware useNot markedCISA KEV ransomware field

Threat actors0Source-linked actor relationships

Overview

What is CVE-2026-17084?

The "stringprep" module didn't process characters from RFC 3454 tables B.2 or B.3 correctly: the latest Unicode codepoint attributes were used instead of the specified Unicode 3.2.0. This behavior would cause mismatches when processing domain names using IDNA 2003 (the "idna" codec) and the in_table_b2() function of the "stringprep" module.

This only affects domain names containing characters that were not previously registered or had their Unicode attributes such as case-folding behavior updated since Unicode 3.2.0.

Source: NVD