---
id: "CVE-2026-129120"
page: "https://infrastack.ai/live/CVE-2026-129120"
kind: "vulnerability"
aliases: ["CVE-2026-129120"]
title: "C-Kermit: malicious server writes files without prompt, enabling code execution"
severity: "medium"
cvss: 5.9
epss: null
exploited: false
status: "open"
category: "other"
products: [{"name": "C-Kermit", "fixed": [], "affected": "", "ecosystem": "vendor"}]
ecosystems: ["vendor"]
tags: ["c-kermit", "kermit", "linux", "other", "unix"]
not_affected_if: ["no-untrusted-kermit-servers"]
published_at: "2026-11-13T17:17:29+00:00"
first_seen_at: "2026-11-13T17:48:00+00:00"
updated_at: "2026-11-13T17:49:06+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-129120", "first_seen_at": "2026-11-13T17:48:00+00:00"}]
exploit_sources: []
---

# C-Kermit: malicious server writes files without prompt, enabling code execution

Link for people: https://infrastack.ai/live/CVE-2026-129120 (this .md is for agents)

C-Kermit 11.0.506 before 11.1.515 lets a malicious Kermit server write files to the client without asking the user, bypassing the RECEIVE CONFIRM check. An attacker can drop files such as .ssh/authorized_keys or shell startup files, which gives persistent access or code execution.

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

## Affected

- vendor:C-Kermit affected range not listed fixed no fixed version listed

## How to check

- Check the installed C-Kermit version with `kermit -v` or the version banner shown on start-up
- Treat any version below `11.1.515` as affected

## Fix

- C-Kermit: `11.1.515`

## Timeline

- 2026-11-13T17:48:00+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-129120

## Documents

- [advisory] Vendor advisory: github.com https://github.com/OpenKermit/ckermit/security/advisories/GHSA-vhrv-7jrq-95qj
- [advisory] Third-party advisory: www.vulncheck.com https://www.vulncheck.com/advisories/c-kermit-11.0.506-before-11.1.515-receive-confirm-bypass-via-recursive-get
- [fix] Patch: github.com https://github.com/OpenKermit/ckermit/commit/49e04a5ccfa08706b1d7e51dce4059f4adce50f3
- [fix] Release notes: github.com https://github.com/OpenKermit/ckermit/releases/tag/v11.1.515

## From the sources

C-Kermit 11.0.506 before 11.1.515 contains a RECEIVE CONFIRM bypass vulnerability that allows malicious Kermit servers to write unrequested files without prompting by abusing recursive GET root computation in ckcfns.c. Attackers can send files such as .ssh/authorized_keys or shell startup files under the current directory, which rq_under_root() accepts silently, enabling persistent access or code execution.

---

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