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Fix: strip Cookie header on cross-origin redirects in RedirectHandler - #2007
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Ramses Sanchez-Hernandez (ramsessanchez) merged 3 commits intoOct 15, 2026
Merged
Ramses Sanchez-Hernandez (ramsessanchez) merged 3 commits into
Ramses Sanchez-Hernandez (ramsessanchez) merged 3 commits into
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The RedirectHandler middleware only removed the Authorization header before following a 3xx redirect to a different origin, while still forwarding the Cookie header to the new host. This allowed session cookies to leak to a different scheme/host/port on redirect. This aligns the behavior with the fix shipped in microsoft-kiota-http-go v1.5.5+, which strips both Authorization and Cookie headers when the redirect target has a different scheme, host, or port than the original request. - Added removeRequestHeader() in MiddlewareUtil.ts, supporting Request, Headers, header-array, and plain-object header representations (case-insensitive key match). - RedirectHandler now drops both Authorization and Cookie headers on cross-origin redirects using the new helper. - Added tests covering Cookie header retention on same-origin redirects and removal (while preserving unrelated custom headers) on cross-origin redirects. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com> Copilot-Session: 6f3ec234-f644-4f5f-835d-575129c4af42
Ramses Sanchez-Hernandez (ramsessanchez)
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October 13, 2026 22:39
Adrian (adrian05-ms)
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Oct 14, 2026
Ramses Sanchez-Hernandez (ramsessanchez)
merged commit Oct 15, 2026
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Security fix: strip Cookie header on cross-origin redirects
Problem
RedirectHandleronly removed theAuthorizationheader before following a 3xx redirect to a different origin. TheCookieheader (and any other forwarded headers) continued to be sent to the new redirect target, including when the redirect pointed to a different scheme, host, or port. This could leak session cookies to an untrusted host.Fix
Aligns this SDK with the fix shipped in
microsoft-kiota-http-gov1.5.5+ (CVE-2026-44503): when a redirect crosses origins (different scheme, host, or port), both theAuthorizationandCookieheaders are now stripped before the redirected request is sent. Other headers are left untouched.Changes
src/middleware/MiddlewareUtil.ts: addedremoveRequestHeader(), a header-removal helper that works across the possibleHeadersInitrepresentations (Request,Headers, header-array, plain object), matching by key case-insensitively.src/middleware/RedirectHandler.ts: added aCOOKIE_HEADERconstant and now removes bothAuthorizationandCookieviaremoveRequestHeader()whenshouldDropAuthorizationHeader()determines the redirect is cross-origin.test/common/middleware/RedirectHandler.ts: added tests verifyingCookieis preserved on same-origin redirects, and that bothAuthorizationandCookieare dropped (while unrelated custom headers are preserved) on cross-origin redirects.Validation
node node_modules\typescript\bin\tsc -b tsconfig-sub-cjs.json— passednode node_modules\mocha\bin\mocha.js --require isomorphic-fetch --reporter dot lib/test/common/**/*.js lib/test/node/**/*.js— 359 passing