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.

Attack Vector Network

Attack Complexity Low

Privileges Required None

Attack Requirements Present

User Interaction Passive

Vulnerable System Confidentiality Impact High

Vulnerable System Integrity Impact High

Vulnerable System Availability Impact None

Subsequent System Confidentiality Impact None

Subsequent System Integrity Impact None

Subsequent System Availability Impact None

Attack Vector Network

Attack Complexity High

Privileges Required None

Scope Unchanged

Confidentiality Impact High

Integrity Impact High

Availability Impact None

User Interaction Required

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

No EPSS score available.

Key SSVC decision points have not yet been added.

Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).

Vendor Product Default status Versions
OpenKermit C-Kermit unaffected
Version Status Constraints
8.0.200 affected < 11.1.515

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Project Subscriptions

No data.

Advisories

No advisories yet.

Fixes

Solution

No solution given by the vendor.

Workaround

No workaround given by the vendor.

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

Fri, 13 Nov 2026 16:30:00 +0000

Type Values Removed Values Added
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.
Title C-Kermit 8.0.200 before 11.1.515 Missing Hostname Verification in AUTHENTICATION SSL
Weaknesses CWE-297
References
Metrics cvssV3_1

{'score': 6.8, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:N'}

cvssV4_0

{'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'}

Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: VulnCheck

Published:

Updated: 2026-11-13T16:23:48.065Z

Reserved: 2026-11-13T16:00:58.608Z

Link: CVE-2026-129117

cve-icon Vulnrichment

No data.

cve-icon NVD

No data.

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

No data.

Weaknesses