CVE-2026-44503 PUBLISHED

Kiota abstractions RedirectHandler leaks Cookie/Proxy-Authorization headers on cross-host redirect

Assigner: GitHub_M
Reserved: 06.05.2026 Published: 14.05.2026 Updated: 14.05.2026

The RedirectHandler middleware in microsoft/kiota-java (com.microsoft.kiota:microsoft-kiota-http-okHttp v1.9.0) and other Kiota libraries fails to strip sensitive HTTP headers when following 3xx redirects to a different host or scheme. Only the Authorization header is removed; Cookie, Proxy-Authorization, and all custom headers are forwarded to the redirect target.

Metrics

CVSS 4.0

CVSS Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:H/VI:N/VA:N/SC:H/SI:N/SA:N
CVSS Score: 7

Exploitability Metrics		Vulnerable System Impact Metrics		Subsequent System Impact Metrics
Attack Vector	Network	Confidentiality	High	Confidentiality	High
Attack Complexity	Low	Integrity	None	Integrity	None
Attack Requirements	Present	Availability	None	Availability	None
Privileges Required	None
User Interaction	Passive

CVSS 4.0

Product Status

Vendor	microsoft
Product	kiota-java
Versions	Version < 1.9.1 is affected

Vendor	microsoft
Product	Microsoft.Kiota.Abstractions
Versions	Version < 1.22.0 is affected

Vendor	microsoft
Product	github.com/microsoft/kiota-http-go
Versions	Version < 1.5.5 is affected

Vendor	microsoft
Product	kiota-typescript
Versions	Version < 1.0.0-preview.100 is affected

Vendor	microsoft
Product	microsoft-kiota-abstractions
Versions	Version < 1.9.1 is affected

Vendor	microsoft
Product	microsoft-kiota-http
Versions	Version < 1.9.9 is affected

References

https://github.com/microsoft/kiota-java/security/advisories/GHSA-7j59-v9qr-6fq9

Problem Types

CWE-601: URL Redirection to Untrusted Site ('Open Redirect') CWE