low3.7
CVE-2026-42040
Axios: Null Byte Injection via Reverse-Encoding in AxiosURLSearchParams
Impact
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 packages
| Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|
| npm | axios | >= 1.0.0, < 1.15.1 | 1.15.1 |
Affected products
| Vendor | Product | Affected versions |
|---|---|---|
| Axios | Axios | before 0.31.1 from 1.0.0 before 1.15.1 |