CVE-2026-59176
Functype: MCP set_functype_version Package Alias RCE via Unsanitized pnpm install + Dynamic Import
Description
Functype is a family of TypeScript functional programming libraries. Prior to 1.4.4, the `set_functype_version` MCP tool in `functype-mcp-server` accepts an unconstrained `version` string using only `z.string()` validation in `packages/mcp-server/src/index.ts` and interpolates it into `functype@<version>` for `pnpm add`. Package-alias syntaxes such as `file:`, `npm:`, URLs, or paths can cause an arbitrary local or remote package to be installed as functype. Immediately afterward, `initDocsData(true)` in `packages/mcp-server/src/lib/docs/data.ts` resolves `functype/cli` and dynamically imports the newly installed module, executing attacker-controlled JavaScript with the MCP server process's privileges. Any MCP client able to send a `tools/call` request invoking the tool can exploit the flaw; the tool is enabled by default without authentication in `stdio` mode. A connected AI assistant susceptible to indirect prompt injection can also be induced to invoke it from a malicious document or web page. In non-default `TRANSPORT_TYPE=httpStream` deployments, a network-accessible attacker does not require local access. Successful execution can read process secrets, modify files, or terminate the server. This issue is fixed in `version` 1.4.4.
INFO
Published Date :
Oct. 28, 2026, 2:17 p.m.
Last Modified :
Nov. 3, 2026, 1:17 p.m.
Remotely Exploit :
No
Source :
[email protected]
Affected Products
The following products are affected by CVE-2026-59176
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 | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | |||||
| CVSS 3.1 | HIGH | github | ||||
| CVSS 3.1 | HIGH | MITRE-CVE | ||||
| CVSS 3.1 | HIGH | [email protected] |
Solution
- Validate package version input to prevent arbitrary package installation.
- Ignore script execution during package installation.
- Ensure package specifiers are safe before installation.
- Install packages using a secure, validated specifier.
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-2026-59176.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-59176 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-2026-59176
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-2026-59176 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-59176 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.
-
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Nov. 03, 2026
Action Type Old Value New Value Added Reference https://github.com/jordanburke/functype/security/advisories/GHSA-wcjj-9m6g-2fr2 Added SSVC {'id': 'CVE-2026-59176', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'poc'}, {'automatable': 'no'}, {'technicalImpact': 'total'}], 'version': '2.0.3', 'timestamp': '2026-11-03T12:57:44.435165Z'} -
New CVE Received by [email protected]
Oct. 28, 2026
Action Type Old Value New Value Added Description Functype is a family of TypeScript functional programming libraries. Prior to 1.4.4, the `set_functype_version` MCP tool in `functype-mcp-server` accepts an unconstrained `version` string using only `z.string()` validation in `packages/mcp-server/src/index.ts` and interpolates it into `functype@<version>` for `pnpm add`. Package-alias syntaxes such as `file:`, `npm:`, URLs, or paths can cause an arbitrary local or remote package to be installed as functype. Immediately afterward, `initDocsData(true)` in `packages/mcp-server/src/lib/docs/data.ts` resolves `functype/cli` and dynamically imports the newly installed module, executing attacker-controlled JavaScript with the MCP server process's privileges. Any MCP client able to send a `tools/call` request invoking the tool can exploit the flaw; the tool is enabled by default without authentication in `stdio` mode. A connected AI assistant susceptible to indirect prompt injection can also be induced to invoke it from a malicious document or web page. In non-default `TRANSPORT_TYPE=httpStream` deployments, a network-accessible attacker does not require local access. Successful execution can read process secrets, modify files, or terminate the server. This issue is fixed in `version` 1.4.4. Added CVSS V3.1 AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H Added CWE CWE-829 Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/59xxx/CVE-2026-59176.json">CVE-2026-59176</a> Added Reference https://github.com/jordanburke/functype/commit/c0d58ad9c2a7d15c6117bd3adbbd75de37317dcf Added Reference https://github.com/jordanburke/functype/releases/tag/v1.4.4 Added Reference https://github.com/jordanburke/functype/security/advisories/GHSA-wcjj-9m6g-2fr2