CVE-2026-129117

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.

Severity scores

Each score is shown as its source gave it. They are not averaged or merged.

• 7.6CVSS 4.0, Highfrom the CNA (VulnCheck)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
• 6.8CVSS 3.1, Mediumfrom the CNA (VulnCheck)CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:N

Historical context and remediation

This reference retains the original CVE publication date. A recent record update does not mean a new attack occurred.

No separately sourced impact summary is available on this page yet. Consult the description, version data and dated exploitation evidence.

No explicit remediation statement is available on this page yet. Consult the original record and vendor references before choosing a fix.

Version statuses below come from the CNA. An “unaffected” version is not necessarily a currently supported release or proof of a patch date. EPSS is a dated risk estimate, not a count of historical attacks.

Read the original CVE record.

Affected products

Timeline

1. 13 Nov 2026 Published

Weakness

• CWE-297

References

• GitHub Security Advisory (GHSA-5pc4-gh6q-5h4w)vendor-advisory
• github.compatch
• C-Kermit v11.1.515 Release Notesrelease-notes
• github.comtechnical-description
• VulnCheck Advisory: C-Kermit 8.0.200 before 11.1.515 Missing Hostname Verification in AUTHENTICATION SSLthird-party-advisory