Microsoft Security Response Center guidance
Vendor revision: Sep 3, 2026See the Microsoft Security Update Guide for the update that applies to your product.
Vulnerability intelligence
CVE-2026-25834 and is rated Medium severity with a CVSS score of 6.5. It is not in the current CISA KEV record we collected. That does not prove exploitation has not occurred.
See the Microsoft Security Update Guide for the update that applies to your product.
Mbed TLS v3.3.0 up to 3.6.5 and 4.0.0 allows Algorithm Downgrade.
Source: NVD