CVE-2026-129117

C-Kermit 8.0.200 before 11.1.515 Missing Hostname Verification in AUTHENTICATION SSL

Published Nov 13, 2026 CVSS 4.0 · 7.6 High EPSS n/a KEV · Not listed

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.

Affected Products

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

No data.

No data available yet.

Remediation

No solution or workaround provided in the CVE record

Tracking

Advisories

No advisories available

Metrics

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.

References

Link	Providers
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

History

Nov 13, 2026 4:30 PM Description updated. Title updated. Weaknesses updated. Added references. Scoring metrics updated View changes

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		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
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'}`