async-http-client: Cookie header not stripped on cross-origin redirect

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

7.4 · CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:N/A:N

EPSS

• CVE-2026-45300: 0.40% estimated exploitation activity in the next 30 days; percentile 34.18 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Summary async-http-client leaks Cookie headers to cross-origin redirect targets. When following a redirect across a security boundary (different origin, or HTTPS→HTTP downgrade), the propagatedHeaders() method in Redirect30xInterceptor.java strips Authorization and Proxy-Authorization headers but does not strip Cookie, so session cookies and other sensitive cookie values are forwarded to the redirect target — which may be attacker-controlled. Details The vulnerability is in client/src/main/java/org/asynchttpclient/netty/handler/intercept/Redirect30xInterceptor.java. The caller computes stripAuth on each redirect: stripAuth is true whenever the redirect crosses an origin, downgrades the scheme, or the caller opted in via AsyncHttpClientConfig#isStripAuthorizationOnRedirect(). In the vulnerable version, propagatedHeaders() only removes Authorization and Proxy-Authorization in that branch — Cookie is left untouched: The companion test class RedirectCredentialSecurityTest covers…

Published by the source

18 May 2026, 16:42 UTC

Last modified by the source

9 Jun 2026, 11:56 UTC

Source last checked

26 Oct 2026, 16:46 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-fmxf-pm6p-7xgm

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# Patch Next advisory brief: CVE-2026-45300

Advisory: async-http-client: Cookie header not stripped on cross-origin redirect
IDs: CVE-2026-45300, GHSA-fmxf-pm6p-7xgm
Record: https://patchnext.com/advisories/cve-2026-45300 (revision 1, source checked 26 Oct 2026, 16:46 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: High (CVSS 7.4)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: org.asynchttpclient:async-http-client 3.0.10, 2.15.0. A vendor fix does not mean a deployment is fixed.

## Affected components
- Maven org.asynchttpclient:async-http-client: affected >= 3.0.0.Beta1, < 3.0.10; >= 2.0.0, < 2.15.0; fixed in 3.0.10, 2.15.0

## Suggested inspection (read-only)
- Maven org.asynchttpclient:async-http-client: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on org.asynchttpclient:async-http-client.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-fmxf-pm6p-7xgm (GitHub-reviewed advisory GHSA-fmxf-pm6p-7xgm lists affected ranges: Maven org.asynchttpclient:async-http-client >=3.0.0.Beta1 =2.0.0 <2.15.0)

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