{"id":"CVE-2026-49336","revision":"c6bfdbd776844089870ec399f034b4eb","records":[{"revision":"c6bfdbd776844089870ec399f034b4eb","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2026-49336","aliases":[],"title":"@microsoft/kiota-http-fetchlibrary: Bearer token and Cookie leak across origin on redirect due to case-mismatched scrub in fetchRequestAdapter","description":"@microsoft/kiota-http-fetchlibrary provides TypeScript libraries for Kiota-generated API clients. In versions 1.0.0-preview.97 through 1.0.0-preview.101, `@microsoft/kiota-http-fetchlibrary`'s `RedirectHandler` is documented as stripping `Authorization` and `Cookie` from cross-origin redirect targets, but the default `scrubSensitiveHeaders` callback in `RedirectHandlerOptions` uses case-sensitive property deletion (`delete headers.Authorization`, `delete headers.Cookie`) on a headers object that `FetchRequestAdapter.getRequestFromRequestInformation` has already lower-cased. The delete therefore targets keys that do not exist, the scrub is a no-op, and any Bearer token or Cookie attached by a kiota-generated SDK is forwarded to an attacker-controlled host across a 30x redirect. This is reachable in the default middleware chain (`MiddlewareFactory.getDefaultMiddlewares`) with no custom configuration, and applies to every kiota-generated TypeScript SDK that uses `BaseBearerTokenAuthenticationProvider` or any other authentication provider that sets the `Authorization` request header. Version 1.0.0-preview.102 patches the issue.","state":0,"publishedAt":"2026-06-19T18:19:03.222+00:00","modifiedAt":"2026-06-22T15:05:46.759+00:00","affected":[{"ecosystem":"Vendor product","name":"kiota-typescript","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"vendor\": \"microsoft\",\n                    \"product\": \"kiota-typescript\",\n                    \"versions\": [\n                        {\n                            \"version\": \">= 1.0.0-preview.97, < 1.0.0-preview.102\",\n                            \"status\": \"affected\"\n                        }\n                    ]\n                }"}],"metrics":[{"system":"CVSS 4.0","vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:P","score":5.5,"severity":"MEDIUM"}],"references":["https://github.com/microsoft/kiota-typescript/security/advisories/GHSA-396q-4vc8-28x9","https://github.com/microsoft/kiota-typescript/commit/09f8bd9b34d68bf412a9b78f6ca7e7961ef14974"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-49336","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-49336","identifiers":["CVE-2026-49336"]},"retained":false,"historicalAffected":[]}],"coverage":[]}