CVE-2026-70367
Stunnel: ssrf bypass in stunnel socks proxy via ipv4-mapped ipv6 loopback and unspecified addresses allows access to loopback-only services
CVSS Score
5.4
EPSS Score
0.2%
EPSS Percentile
5th
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.
| CWE | CWE-918 |
| Vendor | mobi-com polska sp. z o.o. |
| Product | stunnel |
| Published | Aug 4, 2026 |
| Last Updated | Aug 6, 2026 |
Stay Ahead of the Next One
Get instant alerts for mobi-com polska sp. z o.o. stunnel
Be the first to know when new medium vulnerabilities affecting mobi-com polska sp. z o.o. stunnel are published — delivered to Slack, Telegram or Discord.
Get Free Alerts →
Free · No credit card · 60 sec setup
CVSS v3 Breakdown
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N Attack Vector
Network
Attack Complexity
Low
Privileges Required
Low
User Interaction
None
Scope
Unchanged
Confidentiality
Low
Integrity
Low
Availability
None
Affected Versions
Mobi-Com Polska Sp. z o.o. / stunnel
5.25 < 5.80
Red Hat / Red Hat Enterprise Linux 10
All versions affected Red Hat / Red Hat Enterprise Linux 6
All versions affected Red Hat / Red Hat Enterprise Linux 7
All versions affected Red Hat / Red Hat Enterprise Linux 8
All versions affected Red Hat / Red Hat Enterprise Linux 9
All versions affected References
Credits
This issue was discovered by Found by AISLE in partnership with Red Hat.