Stunnel: ssrf bypass in stunnel socks proxy via ipv4-mapped ipv6 loopback and unspecified addresses allows access to loopback-only services

• azl3 stunnel 5.74-1 on Azure Linux 3.0

SecurityAlert records field-level changes from the point we begin following a bulletin. Earlier vendor changes may not have a field-by-field record.

1. Sep 27, 2026 at 11:11 PM UTC
   • The vendor changed its remediation guidance.

1. Aug 7, 2026 at 1:19 AM UTC
   Published by Microsoft Security Response Center

   The publication date reported by the vendor.

2. Aug 20, 2026 at 6:50 PM UTC
   Added to SecurityAlert

   We collected the advisory from the official source.

3. Sep 25, 2026 at 2:35 AM UTC
   Updated by Microsoft Security Response Center

   The vendor changed the advisory after it was first published.

4. Oct 28, 2026 at 3:45 AM UTC
   Confirmed at the source

   Our collector saw this advisory during a later source check.