CVE-2026-129117

high

Description

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.

References

https://www.vulncheck.com/advisories/c-kermit-8.0.200-before-11.1.515-missing-hostname-verification-in-authentication-ssl

https://github.com/OpenKermit/ckermit/security/advisories/GHSA-5pc4-gh6q-5h4w

https://github.com/OpenKermit/ckermit/releases/tag/v11.1.515

https://github.com/OpenKermit/ckermit/commit/0008b429e4fadc8ecfd3d7d661fd55d72e26d527

https://github.com/OpenKermit/ckermit/blob/v11.0.514/ck_ssl.c#L3916

https://euvd.enisa.europa.eu/vulnerability/EUVD-2026-125518

Details

Source: Mitre, NVD

Published: 2026-11-13

Updated: 2026-11-13

Risk Information

CVSS v2

Base Score: 7.1

Vector: CVSS2#AV:N/AC:H/Au:N/C:C/I:C/A:N

Severity: High

CVSS v3

Base Score: 6.8

Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:N

Severity: Medium

CVSS v4

Base Score: 7.6

Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N

Severity: High

EPSS

EPSS: 0.00235