CVE-2026-49336

Summary

@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.

Affected Software

Weaknesses

• CWE-178: CWE-178: Improper Handling of Case Sensitivity
• CWE-200: CWE-200: Exposure of Sensitive Information to an Unauthorized Actor

ADP Enrichment

CISA ADP Vulnrichment

• SSVC:
• Exploitation: poc
  • Automatable: yes
  • Technical Impact: partial

Additional References

• https://github.com/microsoft/kiota-typescript/security/advisories/GHSA-396q-4vc8-28x9

References

• https://github.com/microsoft/kiota-typescript/security/advisories/GHSA-396q-4vc8-28x9
• https://github.com/microsoft/kiota-typescript/commit/09f8bd9b34d68bf412a9b78f6ca7e7961ef14974

• ←Previous
• Next→