CVE-2026-42040

Summary

Axios is a promise based HTTP client for the browser and Node.js. Prior to 1.15.1 and 0.31.1, the encode() function in lib/helpers/AxiosURLSearchParams.js contains a character mapping (charMap) at line 21 that reverses the safe percent-encoding of null bytes. After encodeURIComponent('\x00') correctly produces the safe sequence %00, the charMap entry '%00': '\x00' converts it back to a raw null byte. Primary impact is limited because the standard axios request flow is not affected. This vulnerability is fixed in 1.15.1 and 0.31.1.

Affected Software

VendorProductVersion RangeStatus
axiosaxios>= 1.0.0, < 1.15.1affected
axiosaxios< 0.31.1affected

Weaknesses

  • CWE-116: CWE-116: Improper Encoding or Escaping of Output
  • CWE-626: CWE-626: Null Byte Interaction Error (Poison Null Byte)

ADP Enrichment

CISA ADP Vulnrichment

  • SSVC:
  • Exploitation: poc
    • Automatable: no
    • Technical Impact: partial

Additional References

References