How severe is CVE-2026-44503?

No CVSS score has been assigned to CVE-2026-44503 yet. Review the advisory details and affected package list to assess your exposure.

Which packages are affected by CVE-2026-44503?

CVE-2026-44503 affects the following packages: github.com/microsoft/kiota-http-go (Go), com.microsoft.kiota:microsoft-kiota-abstractions (Maven), kiota-typescript (npm), Microsoft.Kiota.Abstractions (NuGet), microsoft-kiota-http (PyPI). Ecosystems affected: Go, Maven, npm, NuGet, PyPI.

How do I fix CVE-2026-44503?

Update github.com/microsoft/kiota-http-go to 1.5.5 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-44503 is resolved across your whole dependency graph.

How do I detect CVE-2026-44503 in my Go, Maven, npm, NuGet, PyPI dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/microsoft/kiota-http-go. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.

How do I mitigate CVE-2026-44503 if there is no patch (or I can't update yet)?

If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

How does O3 Security protect against CVE-2026-44503?

O3 pinpoints whether CVE-2026-44503 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Is CVE-2026-44503 actively exploited in the wild?

No public exploit code has been indexed for CVE-2026-44503 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

When was CVE-2026-44503 published, and has it been updated?

CVE-2026-44503 was published on May 14, 2026 and was last updated on August 7, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

🐹 Go☕ Maven📦 npm.NET NuGet🐍 PyPI

Not in CISA KEV

CVE-2026-44503

CVE-2026-44503 is a security vulnerability in github.com/microsoft/kiota-http-go. O3 Security confirms whether CVE-2026-44503 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.

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

Also known asGHSA-7j59-v9qr-6fq9GO-2026-5224PYSEC-2026-2647

Published

May 14, 2026

Updated

Aug 7, 2026

Affected

5 pkgs

Patched

5 / 5

Exploits

None indexed

Exploitation data as of Aug 7, 2026 · OSV.dev, FIRST.org (EPSS)

Real-World Exposure

5 pkgs affected

🐹github.com/microsoft/kiota-http-go☕com.microsoft.kiota:microsoft-kiota-abstractions📦kiota-typescript.NETMicrosoft.Kiota.Abstractions🐍microsoft-kiota-http

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects Go, Maven, npm packages — download data is not available via public APIs for these ecosystems.

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 Packages

5 total 5 fixed

Ecosystem	Package	Vulnerable range	Fix
🐹Go	`github.com/microsoft/kiota-http-go`	all versions	1.5.5
☕Maven	`com.microsoft.kiota:microsoft-kiota-abstractions`	all versions	1.9.1
📦npm	`kiota-typescript`	all versions	1.0.0-preview.100
.NETNuGet	`Microsoft.Kiota.Abstractions`	all versions	1.22.0
🐍PyPI	`microsoft-kiota-http`	all versions	1.9.9

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/microsoft/kiota-http-go. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update github.com/microsoft/kiota-http-go to 1.5.5 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-44503 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether CVE-2026-44503 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Tailored to CVE-2026-44503. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

O3 Security · Impact-Aware SCA

Is CVE-2026-44503 in your dependencies?

O3 detects CVE-2026-44503 across Go, Maven, npm dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.

Scan my dependencies How O3 SCA works