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OpenAdvisories
Medium · 6.8 CVE-2026-40490 EUVD-2026-23638GHSA-cmxv-58fp-fm3g

AsyncHttpClient leaks authorization credentials to untrusted domains on cross-origin redirects

Published Apr 18, 2026 · Updated Apr 20, 2026 · Assigned by GitHub_M

Description

The AsyncHttpClient (AHC) library allows Java applications to easily execute HTTP requests and asynchronously process HTTP responses. When redirect following is enabled (followRedirect(true)), versions of AsyncHttpClient prior to 3.0.9 and 2.14.5 forward Authorization and Proxy-Authorization headers along with Realm credentials to arbitrary redirect targets regardless of domain, scheme, or port changes. This leaks credentials on cross-domain redirects and HTTPS-to-HTTP downgrades. Additionally, even when stripAuthorizationOnRedirect is set to true, the Realm object containing plaintext credentials is still propagated to the redirect request, causing credential re-generation for Basic and Digest authentication schemes via NettyRequestFactory. An attacker who controls a redirect target (via open redirect, DNS rebinding, or MITM on HTTP) can capture Bearer tokens, Basic auth credentials, or any other Authorization header value. The fix in versions 3.0.9 and 2.14.5 automatically strips Authorization and Proxy-Authorization headers and clears Realm credentials whenever a redirect crosses origin boundaries (different scheme, host, or port) or downgrades from HTTPS to HTTP. For users unable to upgrade, set `(stripAuthorizationOnRedirect(true))` in the client config and avoid using Realm-based authentication with redirect following enabled. Note that `(stripAuthorizationOnRedirect(true))` alone is insufficient on versions prior to 3.0.9 and 2.14.5 because the Realm bypass still re-generates credentials. Alternatively, disable redirect following (`followRedirect(false)`) and handle redirects manually with origin validation.

Affected products

VendorProductAffectedFixed
AsyncHttpClient async-http-client >= 3.0.0.Beta1, < 3.0.9, < 2.14.5 —

Fixed in Linux distributions

Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.

ReleasePackageFixed inAdvisory
Debian 12 async-http-client No fix yet —
ReleasePackageFixed inAdvisory
Ubuntu 26.10 async-http-client No fix yet —
Ubuntu 26.04 LTS async-http-client No fix yet —
Ubuntu 25.10 async-http-client No fix yet —
Ubuntu 24.04 LTS async-http-client No fix yet —
Ubuntu 22.04 LTS async-http-client No fix yet —
Show 4 more (older releases, extended support, other products)
ReleasePackageFixed inAdvisory
Ubuntu 18.04 LTS async-http-client No fix yet —
Ubuntu 16.04 LTS async-http-client No fix yet —
Ubuntu Pro 20.04 LTS async-http-client No fix yet —
Ubuntu Pro 14.04 LTS async-http-client No fix yet —

Wolfi

ReleasePackageFixed inAdvisory
Wolfi rolling apache-pulsar-4.2 4.2.1-r0 —
Wolfi rolling druid 36.0.0-r15 —
Wolfi rolling tez 0.10.5-r11 —

Affected packages

EcosystemPackageAffectedFixedRecord
Maven org.asynchttpclient:async-http-client >= 3.0.0.Beta1, < 3.0.9 3.0.9 GHSA-cmxv-58fp-fm3g
Maven org.asynchttpclient:async-http-client >= 2.0.0, < 2.14.5 2.14.5 GHSA-cmxv-58fp-fm3g

References