Advisoriesby IbisRed HatCVE-2026-70367
Red Hat stunnel: server-side request forgery
Fix: upgrade to 5.80 or later
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 versions
| Package | Affected | Fixed in |
|---|---|---|
| Red Hat Enterprise Linux 10 Product | all versions | No fix yet |
| Red Hat Enterprise Linux 6 Product | all versions | No fix yet |
| Red Hat Enterprise Linux 7 Product | all versions | No fix yet |
| Red Hat Enterprise Linux 8 Product | all versions | No fix yet |
| Red Hat Enterprise Linux 9 Product | all versions | No fix yet |
| stunnel Product | >= 5.25, < 5.80 | 5.80 |
Details and references
- CVSS 3.1
- CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N
- Severity from
- the vendor (its own CVE record or advisory)
- Weakness
- CWE-918