{"id":"GHSA-7ch4-rr99-cqcw","summary":"gatsby-transformer-remark has possible unsanitized JavaScript code injection","details":"### Impact\nThe gatsby-transformer-remark plugin prior to versions 5.25.1 and 6.3.2 passes input through to the `gray-matter` npm package, which is vulnerable to JavaScript injection in its default configuration, unless input is sanitized.  The vulnerability is present in gatsby-transformer-remark when passing input in data mode (querying MarkdownRemark nodes via GraphQL).  Injected JavaScript executes in the context of the build server.\n\nTo exploit this vulnerability untrusted/unsanitized input would need to be sourced by or added into a file processed by gatsby-transformer-remark.  The following payload demonstrates a vulnerable configuration:\n```\n---js\n((require(\"child_process\")).execSync(\"id \u003e\u003e /tmp/rce\"))\n--- \n```\n\n### Patches\nA patch has been introduced in `gatsby-transformer-remark@5.25.1` and `gatsby-transformer-remark@6.3.2` which mitigates the issue by disabling the `gray-matter` JavaScript Frontmatter engine.  The patch introduces a new option, `JSFrontmatterEngine` which is set to `false` by default.  When setting `JSFrontmatterEngine` to `true`, input passed to `gatsby-plugin-mdx` must be sanitized before processing to avoid a security risk.  Warnings are displayed when enabling `JSFrontmatterEngine` to `true` or if it appears that the MarkdownRemark input is attempting to use the Frontmatter engine.\n\n### Workarounds\nIf an older version of `gatsby-transformer-remark` must be used, input passed into the plugin should be sanitized ahead of processing.\n\n**We encourage projects to upgrade to the latest major release branch for all Gatsby plugins to ensure the latest security updates and bug fixes are received in a timely manner.**\n\n\n### For more information\nEmail us at [security@gatsbyjs.com](mailto:security@gatsbyjs.com).","aliases":["CVE-2023-22491"],"modified":"2026-09-10T03:49:51.023290486Z","published":"2023-01-11T18:27:15Z","database_specific":{"severity":"HIGH","github_reviewed":true,"github_reviewed_at":"2023-01-11T18:27:15Z","nvd_published_at":"2023-01-13T19:15:00Z","cwe_ids":["CWE-20","CWE-79"]},"references":[{"type":"WEB","url":"https://github.com/gatsbyjs/gatsby/security/advisories/GHSA-7ch4-rr99-cqcw"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2023-22491"},{"type":"PACKAGE","url":"https://github.com/gatsbyjs/gatsby"}],"affected":[{"package":{"name":"gatsby-transformer-remark","ecosystem":"npm","purl":"pkg:npm/gatsby-transformer-remark"},"ranges":[{"type":"SEMVER","events":[{"introduced":"6.0.0"},{"fixed":"6.3.2"}]}],"database_specific":{"source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2023/01/GHSA-7ch4-rr99-cqcw/GHSA-7ch4-rr99-cqcw.json"}},{"package":{"name":"gatsby-transformer-remark","ecosystem":"npm","purl":"pkg:npm/gatsby-transformer-remark"},"ranges":[{"type":"SEMVER","events":[{"introduced":"0"},{"fixed":"5.25.1"}]}],"database_specific":{"source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2023/01/GHSA-7ch4-rr99-cqcw/GHSA-7ch4-rr99-cqcw.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N"}]}