CVE-2026-86541
knowns before 0.30.0 Path Traversal via code.replace MCP action
Description
knowns versions before 0.30.0 contain a path traversal vulnerability in the handleCodeReplace() function that allows attackers to overwrite arbitrary files outside the project root. Attackers can supply absolute paths or relative paths containing directory traversal sequences to write malicious content to sensitive files like shell startup scripts or SSH configuration files.
INFO
Published Date :
Sept. 7, 2026, 11:16 p.m.
Last Modified :
Sept. 7, 2026, 11:16 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
Affected Products
The following products are affected by CVE-2026-86541
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
No affected product recoded yet
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | HIGH | 83251b91-4cc7-4094-a5c7-464a1b83ea10 | ||||
| CVSS 3.1 | HIGH | [email protected] | ||||
| CVSS 4.0 | HIGH | 83251b91-4cc7-4094-a5c7-464a1b83ea10 | ||||
| CVSS 4.0 | HIGH | [email protected] |
Solution
- Update the software to version 0.30.0 or later.
- Validate file permissions and ownership.
- Review overwritten files for malicious content.
- Implement input validation for file paths.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-86541.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-86541 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-86541
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-86541 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-86541 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
New CVE Received by [email protected]
Sep. 07, 2026
Action Type Old Value New Value Added Description knowns versions before 0.30.0 contain a path traversal vulnerability in the handleCodeReplace() function that allows attackers to overwrite arbitrary files outside the project root. Attackers can supply absolute paths or relative paths containing directory traversal sequences to write malicious content to sensitive files like shell startup scripts or SSH configuration files. Added CVSS V4.0 AV:N/AC:L/AT:N/PR:N/UI:P/VC:L/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X Added CVSS V3.1 AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:H/A:H Added CWE CWE-22 Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/86xxx/CVE-2026-86541.json">CVE-2026-86541</a> Added Reference https://github.com/knowns-dev/knowns/blob/v0.29.1/internal/mcp/handlers/code.go#L588-L646 Added Reference https://github.com/knowns-dev/knowns/commit/a2c98fc5c313463576c9348beeec6a74ddd7333b Added Reference https://github.com/knowns-dev/knowns/releases/tag/v0.30.0 Added Reference https://github.com/knowns-dev/knowns/security/advisories/GHSA-f539-xgc6-xw7q Added Reference https://www.vulncheck.com/advisories/knowns-before-0.30.0-path-traversal-via-code-replace-mcp-action