SymCrypt SymCryptXmssSign function - Heap overflow via 64->32-bit leaf-count truncation

Scope

What the vendor says is affected

• azl3 SymCrypt 103.8.0-1 on Azure Linux 3.0

Timeline

When this advisory changed

1. Apr 17, 2026 at 1:02 AM UTC
   Published by Microsoft Security Response Center

   The publication date reported by the vendor.

2. Sep 27, 2026 at 11:11 PM UTC
   Added to SecurityAlert

   We collected the advisory from the official source.

Vulnerabilities

CVEs named in this advisory

CVE-2026-35199View CVSS, KEV, EPSS, and threat context