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

[ Why it matters ]Priority signals

• Public proof-of-concept exploit exists (CISA SSVC)

[ Description ]Official description

Axios is a promise-based HTTP client for the browser and Node.js. From 1.16.1 until 1.20.0, the RFC 2397 regular expression allows slash characters on both sides of the media-type separator. An application passes an attacker-controlled malformed data URL containing many slash characters and no comma. the JavaScript regular-expression engine explores many separator placements before rejecting the URL. Synchronous excessive backtracking can block the Node.js event loop and cause denial of service. The affected identifiers are fromDataURI, DATA_URL_PATTERN, data:. This issue is fixed in version 1.20.0.

[ Fixes ]Fixes and patches

• axios 1.20.0Fixed version · GitHub Advisories · npm package axios: upgrade to 1.20.0 or later (affected >= 1.16.1, < 1.20.0)

[ Advisories ]Government CERT advisories

• BSI CERT-Bund20 Oct 2026WID-SEC-2026-4056

  Atlassian products (Bamboo, Bitbucket, Confluence, Crucible, Fisheye and Jira): Multiple vulnerabilities Translated from German

  CVE-2026-13676CVE-2026-50750CVE-2026-53404+72 more CVEs

[ Packages ]Affected open-source packages

• axios npmAffected >= 1.16.1, < 1.20.0 · fixed in 1.20.0 · GHSA-c29m-xwm3-cm6r

[ References ]References

• github.com/axios/axios/commit/d19040bda7a8be2f82c3c6e1a5bc03917daee39a
• github.com/axios/axios/pull/11141
• github.com/axios/axios/releases/tag/v1.20.0
• github.com/axios/axios/security/advisories/GHSA-c29m-xwm3-cm6r