{"id":"CVE-2026-42040","state":"PUBLISHED","title":"Axios: Null Byte Injection via Reverse-Encoding in AxiosURLSearchParams","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.","publishedAt":"2026-04-24T17:40:31.125Z","updatedAt":"2026-04-27T13:48:06.659Z","severity":{"score":3.7,"label":"Low","version":"3.1","vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N","source":"GitHub_M"},"assigner":"GitHub_M","products":["axios axios"],"affected":[{"vendor":"axios","product":"axios","versions":[{"version":">= 1.0.0, < 1.15.1","status":"affected"},{"version":"< 0.31.1","status":"affected"}]}],"references":["https://github.com/axios/axios/security/advisories/GHSA-xhjh-pmcv-23jw"],"weaknesses":["CWE-116","CWE-626"],"ingestedAt":"2026-10-29T20:11:57.932Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/42xxx/CVE-2026-42040.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-42040","state":"PUBLISHED","datePublished":"2026-04-24T17:40:31.125Z","dateUpdated":"2026-04-27T13:48:06.659Z","assignerShortName":"GitHub_M","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateReserved":"2026-04-23T16:05:01.709Z"},"containers":{"cna":{"title":"Axios: Null Byte Injection via Reverse-Encoding in AxiosURLSearchParams","descriptions":[{"lang":"en","value":"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":[{"vendor":"axios","product":"axios","versions":[{"version":">= 1.0.0, < 1.15.1","status":"affected"},{"version":"< 0.31.1","status":"affected"}]}],"references":[{"url":"https://github.com/axios/axios/security/advisories/GHSA-xhjh-pmcv-23jw","name":"https://github.com/axios/axios/security/advisories/GHSA-xhjh-pmcv-23jw","tags":["x_refsource_CONFIRM"]}],"metrics":[{"cvssV3_1":{"attackComplexity":"HIGH","attackVector":"NETWORK","availabilityImpact":"NONE","baseScore":3.7,"baseSeverity":"LOW","confidentialityImpact":"NONE","integrityImpact":"LOW","privilegesRequired":"NONE","scope":"UNCHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N","version":"3.1"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-116","lang":"en","description":"CWE-116: Improper Encoding or Escaping of Output","type":"CWE"}]},{"descriptions":[{"cweId":"CWE-626","lang":"en","description":"CWE-626: Null Byte Interaction Error (Poison Null Byte)","type":"CWE"}]}],"providerMetadata":{"shortName":"GitHub_M","orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateUpdated":"2026-04-24T17:40:31.125Z"},"source":{"advisory":"GHSA-xhjh-pmcv-23jw","discovery":"UNKNOWN"}},"adp":[{"title":"CISA ADP Vulnrichment","references":[{"url":"https://github.com/axios/axios/security/advisories/GHSA-xhjh-pmcv-23jw","tags":["exploit"]}],"metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-04-27T13:48:02.943460Z","id":"CVE-2026-42040","options":[{"Exploitation":"poc"},{"Automatable":"no"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-04-27T13:48:06.659Z"}}]}}}