CVE-2026-129117

CVSS 7.6 (high) · published 2026-11-13

C-Kermit 8.0.200 before 11.1.515 contains an improper certificate validation vulnerability that allows machine-in-the-middle attackers to impersonate Telnet servers because ssl_reply() never calls ssl_check_server_name(). Attackers can refuse START-TLS, offer Telnet AUTHENTICATION SSL, and present any trusted CA certificate to capture user credentials and session data.

Weakness: CWE-297

Source: NVD CVE-2026-129117

References

• https://github.com/OpenKermit/ckermit/blob/v11.0.514/ck_ssl.c#L3916
• https://github.com/OpenKermit/ckermit/commit/0008b429e4fadc8ecfd3d7d661fd55d72e26d527
• https://github.com/OpenKermit/ckermit/releases/tag/v11.1.515
• https://github.com/OpenKermit/ckermit/security/advisories/GHSA-5pc4-gh6q-5h4w
• https://www.vulncheck.com/advisories/c-kermit-8.0.200-before-11.1.515-missing-hostname-verification-in-authentication-ssl

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