Gatsby is a free and open source framework based on React that helps
developers build websites and apps. The 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. To exploit this vulnerability
untrusted/unsanitized input would need to be sourced by or added into a
file processed by gatsby-transformer-remark. A patch has been introduced in
`[email protected]` and `[email protected]`
which mitigates the issue by disabling the `gray-matter` JavaScript
Frontmatter engine. As a workaround, if an older version of
`gatsby-transformer-remark` must be used, input passed into the plugin
should be sanitized ahead of processing. It is encouraged for 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.Read More