CVE-2026-101903: Axios: ReDoS in fromDataURI data: URL parser freezes the Node event loop (DoS)

Axios for Node.js parses data: URLs in lib/helpers/fromDataURI.js. The current RFC-2397 parser uses a regular expression whose media type groups allow / inside both sides of the type/subtype match. A malformed data: URL containing many slashes and no comma forces the JavaScript regex engine to try many possible placements for the separator before failing.

Applications are affected when they pass untrusted URL strings to axios and do not reject or constrain data: URLs before axios parses them.