{"cve":"CVE-2026-49336","nvd":{"published":"2026-06-19T19:16:36.430","modified":"2026-10-25T23:10:00.167","status":"Deferred","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.","cvss_v4":{"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},"cvss_v3":null,"cwes":["CWE-178","CWE-200"],"references":["https://github.com/microsoft/kiota-typescript/commit/09f8bd9b34d68bf412a9b78f6ca7e7961ef14974","https://github.com/microsoft/kiota-typescript/security/advisories/GHSA-396q-4vc8-28x9","https://github.com/microsoft/kiota-typescript/security/advisories/GHSA-396q-4vc8-28x9"],"products":[],"source":"nvd","synced_at":"2026-10-25T23:44:33.281319194+00:00"},"epss":{"cve":"CVE-2026-49336","score":0.01178,"percentile":0.67428,"date":"2026-10-25"},"kev":null,"osv":[{"id":"GHSA-396q-4vc8-28x9","url":"https://osv.dev/vulnerability/GHSA-396q-4vc8-28x9","summary":"@microsoft/kiota-http-fetchlibrary: Bearer token and Cookie leak across origin on redirect due to case-mismatched scrub in fetchRequestAdapter","modified":"2026-09-10T03:50:55.345787360Z","packages":[{"ecosystem":"npm","name":"@microsoft/kiota-http-fetchlibrary","purl":"pkg:npm/%40microsoft/kiota-http-fetchlibrary","ranges":[">=1.0.0-preview.97 <1.0.0-preview.102"],"fixed":["1.0.0-preview.102"]}]}],"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."]}