What’s Vulnerable › Vulnerabilities

CVE-2026-44503: Kiota abstractions RedirectHandler leaks Cookie/Proxy-Authorization headers on cross-host redirect

• Severity: high (CVSS 7.0 v4.0)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.6% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-05-14 · updated 2026-10-26
• Weakness: CWE-601

Description

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.

Affected products

• microsoft github.com/microsoft/kiota-http-go: before 1.5.5
• microsoft kiota-java: before 1.9.1
• microsoft kiota-typescript: before 1.0.0-preview.100
• microsoft-kiota-abstractions: before 1.9.1
• microsoft-kiota-http: before 1.9.9
• Microsoft.Kiota.Abstractions: before 1.22.0

References

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

Get alerted when CVE-2026-44503 or the next vulnerability affects your stack