---
id: "CVE-2026-129118"
page: "https://infrastack.ai/live/CVE-2026-129118"
kind: "vulnerability"
aliases: ["CVE-2026-129118"]
title: "C-Kermit: wildcard certificate matching lets attackers impersonate hosts over TLS"
severity: "high"
cvss: 7.6
epss: null
exploited: false
status: "open"
category: "package"
products: []
ecosystems: []
tags: ["c-kermit", "ftp", "package", "telnet", "tls"]
not_affected_if: ["no-tls-use", "versions-outside-range"]
published_at: "2026-11-13T17:17:28+00:00"
first_seen_at: "2026-11-13T17:48:00+00:00"
updated_at: "2026-11-13T17:48:51+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-129118", "first_seen_at": "2026-11-13T17:48:00+00:00"}]
exploit_sources: []
---

# C-Kermit: wildcard certificate matching lets attackers impersonate hosts over TLS

Link for people: https://infrastack.ai/live/CVE-2026-129118 (this .md is for agents)

C-Kermit mishandles hostname checks in its TLS certificate code, so names containing asterisks, question marks, brackets or empty labels match when they should not. An attacker holding a trusted certificate with such names can intercept credentials and data sent over Telnet, FTP and HTTP TLS connections.

_Summary, check and fix written by a model from the sources; labelled as such._

## How to check

- Check the installed C-Kermit version with `kermit -v` or the package manager; affected versions are 8.0.200 up to but not including 11.1.515.
- Look for uses of C-Kermit that make TLS connections over Telnet, FTP or HTTP.

## Fix

- C-Kermit: move to `11.1.515` or later (per the NVD range, fixed in 11.1.515).

## Timeline

- 2026-11-13T17:48:00+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-129118

## Documents

- [advisory] Vendor advisory: github.com https://github.com/OpenKermit/ckermit/security/advisories/GHSA-5pc4-gh6q-5h4w
- [advisory] Third-party advisory: www.vulncheck.com https://www.vulncheck.com/advisories/c-kermit-8.0.200-before-11.1.515-improper-certificate-hostname-matching-via-dnsname-cmp
- [fix] Patch: github.com https://github.com/OpenKermit/ckermit/commit/8c60a2bd70f5a78e77ce5d140a17e7a9cdcd5e60
- [fix] Release notes: github.com https://github.com/OpenKermit/ckermit/releases/tag/v11.1.515

## From the sources

C-Kermit 8.0.200 before 11.1.515 contains an improper certificate hostname validation vulnerability that allows attackers to impersonate hosts by abusing wildcard matching in dNSName_cmp() in ck_ssl.c. Attackers holding a trusted certificate with over-matching names containing asterisks, question marks, brackets, or empty labels can intercept credentials and data over Telnet, FTP, and HTTP TLS connections.

---

_Free to read, with fair use of about 60 pages a minute. For higher limits or API access: sales@infrastack.ai_