CVE-2026-70367: Mobi-Com Polska Sp. Z O.o Stunnel

Medium severity, CVSS 5.4. EPSS: 0.3% chance of exploitation in the next 30 days.

A Server-Side Request Forgery (SSRF) bypass vulnerability exists in “stunnel” 5.79 and lower when configured in SOCKS proxy mode. This flaw allows a client to bypass intended localhost restrictions by using IPv4-mapped IPv6 addresses (e.g., “::ffff:127.0.0.1”) or unspecified addresses ("0.0.0.0", "::"), enabling access to loopback-only services on the "stunnel" host that should not be network-reachable.

Affected products

• Mobi-Com Polska Sp. Z O.o Stunnel: from 5.25, before 5.80 (fixed in 5.80)
• Red Hat Red Hat Enterprise Linux 10
• Red Hat Red Hat Enterprise Linux 6
• Red Hat Red Hat Enterprise Linux 7
• Red Hat Red Hat Enterprise Linux 8
• Red Hat Red Hat Enterprise Linux 9

Published 2026-08-04. Last modified 2026-08-06.