{"id":"CVE-2026-111756","state":"PUBLISHED","title":"follow-redirects array-form headers bypass cross-origin credential stripping","description":"follow-redirects is a Node.js HTTP and HTTPS client wrapper that automatically follows redirects. From version 1.16.0 to before version 1.16.1, follow-redirects removes sensitive credential headers (Authorization, Proxy-Authorization, Cookie, and any caller-declared sensitiveHeaders) before following a redirect that crosses to a different host or downgrades to a less secure protocol. The removal routine iterates the caller's headers container with for...in and matches header names against a filter. This assumes the headers container is a plain object keyed by header names. Node's underlying http.request, which follow-redirects is a drop-in replacement for, also accepts headers as an alternating array of names and values. For an array, for...in yields the numeric indices \"0\", \"1\", \"2\" and so on, which never match a header-name filter, so nothing is removed. An application that sends array-form headers and follows an attacker-controlled cross-origin redirect therefore forwards its Authorization, Cookie, and Proxy-Authorization headers verbatim to the attacker-controlled destination, with no error or warning. The sensitiveHeaders option added to fix CVE-2026-40895 / GHSA-r4q5-vmmm-2653 is equally ineffective, because it relies on the same helper. This is an unauthenticated confidentiality vulnerability: any remote server the victim application contacts can harvest the victim's credential headers by responding with a cross-origin redirect. This issue has been patched in version 1.16.1.","publishedAt":"2026-10-20T17:58:21.005Z","updatedAt":"2026-10-23T01:59:26.728Z","severity":{"score":8.2,"label":"High","version":"4.0","vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N","source":"GitHub_M"},"assigner":"GitHub_M","products":["follow-redirects follow-redirects"],"affected":[{"vendor":"follow-redirects","product":"follow-redirects","versions":[{"version":">= 1.16.0, < 1.16.1","status":"affected"}]}],"references":["https://github.com/follow-redirects/follow-redirects/security/advisories/GHSA-q3jh-wrc6-jgq8","https://github.com/follow-redirects/follow-redirects/commit/9865ca45490e4d0f7b6944870318408344570aff","https://github.com/follow-redirects/follow-redirects/releases/tag/v1.16.1"],"weaknesses":["CWE-200","CWE-212"],"ingestedAt":"2026-10-29T20:10:33.477Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/111xxx/CVE-2026-111756.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-111756","state":"PUBLISHED","datePublished":"2026-10-20T17:58:21.005Z","dateUpdated":"2026-10-23T01:59:26.728Z","assignerShortName":"GitHub_M","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateReserved":"2026-10-16T17:52:09.081Z"},"containers":{"cna":{"title":"follow-redirects array-form headers bypass cross-origin credential stripping","descriptions":[{"lang":"en","value":"follow-redirects is a Node.js HTTP and HTTPS client wrapper that automatically follows redirects. From version 1.16.0 to before version 1.16.1, follow-redirects removes sensitive credential headers (Authorization, Proxy-Authorization, Cookie, and any caller-declared sensitiveHeaders) before following a redirect that crosses to a different host or downgrades to a less secure protocol. The removal routine iterates the caller's headers container with for...in and matches header names against a filter. This assumes the headers container is a plain object keyed by header names. Node's underlying http.request, which follow-redirects is a drop-in replacement for, also accepts headers as an alternating array of names and values. For an array, for...in yields the numeric indices \"0\", \"1\", \"2\" and so on, which never match a header-name filter, so nothing is removed. An application that sends array-form headers and follows an attacker-controlled cross-origin redirect therefore forwards its Authorization, Cookie, and Proxy-Authorization headers verbatim to the attacker-controlled destination, with no error or warning. The sensitiveHeaders option added to fix CVE-2026-40895 / GHSA-r4q5-vmmm-2653 is equally ineffective, because it relies on the same helper. This is an unauthenticated confidentiality vulnerability: any remote server the victim application contacts can harvest the victim's credential headers by responding with a cross-origin redirect. This issue has been patched in version 1.16.1."}],"affected":[{"vendor":"follow-redirects","product":"follow-redirects","versions":[{"version":">= 1.16.0, < 1.16.1","status":"affected"}]}],"references":[{"url":"https://github.com/follow-redirects/follow-redirects/security/advisories/GHSA-q3jh-wrc6-jgq8","name":"https://github.com/follow-redirects/follow-redirects/security/advisories/GHSA-q3jh-wrc6-jgq8","tags":["x_refsource_CONFIRM"]},{"url":"https://github.com/follow-redirects/follow-redirects/commit/9865ca45490e4d0f7b6944870318408344570aff","name":"https://github.com/follow-redirects/follow-redirects/commit/9865ca45490e4d0f7b6944870318408344570aff","tags":["x_refsource_MISC"]},{"url":"https://github.com/follow-redirects/follow-redirects/releases/tag/v1.16.1","name":"https://github.com/follow-redirects/follow-redirects/releases/tag/v1.16.1","tags":["x_refsource_MISC"]}],"metrics":[{"cvssV4_0":{"attackVector":"NETWORK","attackComplexity":"LOW","attackRequirements":"PRESENT","privilegesRequired":"NONE","userInteraction":"NONE","vulnConfidentialityImpact":"HIGH","vulnIntegrityImpact":"NONE","vulnAvailabilityImpact":"NONE","subConfidentialityImpact":"NONE","subIntegrityImpact":"NONE","subAvailabilityImpact":"NONE","baseScore":8.2,"baseSeverity":"HIGH","vectorString":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N","version":"4.0"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-200","lang":"en","description":"CWE-200: Exposure of Sensitive Information to an Unauthorized Actor","type":"CWE"}]},{"descriptions":[{"cweId":"CWE-212","lang":"en","description":"CWE-212: Improper Removal of Sensitive Information Before Storage or Transfer","type":"CWE"}]}],"providerMetadata":{"shortName":"GitHub_M","orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateUpdated":"2026-10-20T17:58:21.005Z"},"source":{"advisory":"GHSA-q3jh-wrc6-jgq8","discovery":"UNKNOWN"}},"adp":[{"title":"CISA ADP Vulnrichment","references":[{"url":"https://github.com/follow-redirects/follow-redirects/security/advisories/GHSA-q3jh-wrc6-jgq8","tags":["exploit"]}],"metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-10-23T01:59:05.315622Z","id":"CVE-2026-111756","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":"2026-10-23T01:59:26.728Z"}}]}}}