{"id":"CVE-2026-59176","sourceIdentifier":"security-advisories@github.com","published":"2026-10-28T14:17:04.593","lastModified":"2026-10-28T15:24:56.033","vulnStatus":"Deferred","cveTags":[],"descriptions":[{"lang":"en","value":"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."}],"affected":[{"source":"security-advisories@github.com","affectedData":[{"vendor":"jordanburke","product":"functype","versions":[{"version":"< 1.4.4","status":"affected"}]}]}],"metrics":{"cvssMetricV31":[{"source":"security-advisories@github.com","type":"Secondary","cvssData":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H","baseScore":7.8,"baseSeverity":"HIGH","attackVector":"LOCAL","attackComplexity":"LOW","privilegesRequired":"NONE","userInteraction":"REQUIRED","scope":"UNCHANGED","confidentialityImpact":"HIGH","integrityImpact":"HIGH","availabilityImpact":"HIGH"},"exploitabilityScore":1.8,"impactScore":5.9}]},"weaknesses":[{"source":"security-advisories@github.com","type":"Primary","description":[{"lang":"en","value":"CWE-829"}]}],"references":[{"url":"https://github.com/jordanburke/functype/commit/c0d58ad9c2a7d15c6117bd3adbbd75de37317dcf","source":"security-advisories@github.com"},{"url":"https://github.com/jordanburke/functype/releases/tag/v1.4.4","source":"security-advisories@github.com"},{"url":"https://github.com/jordanburke/functype/security/advisories/GHSA-wcjj-9m6g-2fr2","source":"security-advisories@github.com"}]}