{"cve":"CVE-2026-42040","nvd":{"published":"2026-04-24T18:16:30.960","modified":"2026-06-17T10:47:21.197","status":"Analyzed","description":"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.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N","score":3.7},"cwes":["CWE-116","CWE-626"],"references":["https://github.com/axios/axios/security/advisories/GHSA-xhjh-pmcv-23jw","https://github.com/axios/axios/security/advisories/GHSA-xhjh-pmcv-23jw"],"products":["axios:axios"],"source":"nvd","synced_at":"2026-10-19T22:33:09.003606135+00:00"},"epss":{"cve":"CVE-2026-42040","score":0.00217,"percentile":0.12184,"date":"2026-11-01"},"kev":null,"osv":[{"id":"GHSA-xhjh-pmcv-23jw","url":"https://osv.dev/vulnerability/GHSA-xhjh-pmcv-23jw","summary":"Axios: Null Byte Injection via Reverse-Encoding in AxiosURLSearchParams","modified":"2026-09-10T03:50:48.032269033Z","packages":[{"ecosystem":"npm","name":"axios","purl":"pkg:npm/axios","ranges":[">=1.0.0 <1.15.1"],"fixed":["1.15.1"]},{"ecosystem":"npm","name":"axios","purl":"pkg:npm/axios","ranges":["<0.31.1"],"fixed":["0.31.1"]}]}],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}