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6.8
AsyncHttpClient leaks credentials on redirects to untrusted domains
GHSA-cmxv-58fp-fm3g
Summary
A security issue affects AsyncHttpClient, allowing an attacker to steal credentials when the software redirects to a different domain. This can happen when the software is configured to follow redirects. To fix this, update to version 3.0.9 or, if that's not possible, disable redirect following or use alternative authentication methods.
What to do
- Update asynchttpclient org.asynchttpclient:async-http-client to version 3.0.9.
Affected software
| Ecosystem | Vendor | Product | Affected versions |
|---|---|---|---|
| maven | asynchttpclient | org.asynchttpclient:async-http-client |
< 3.0.9 Fix: upgrade to 3.0.9
|
Original title
AsyncHttpClient leaks authorization credentialsto untrusted domains on cross-origin redirects
Original description
### Impact
When redirect following is enabled (followRedirect(true)), AsyncHttpClient forwards 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.
### Patches
Fixed in version 3.0.9. Users should upgrade immediately.
The fix 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.
### Workarounds
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 because the Realm bypass still re-generates credentials.
Alternatively, disable redirect following (followRedirect(false)) and handle redirects manually with origin validation.
When redirect following is enabled (followRedirect(true)), AsyncHttpClient forwards 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.
### Patches
Fixed in version 3.0.9. Users should upgrade immediately.
The fix 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.
### Workarounds
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 because the Realm bypass still re-generates credentials.
Alternatively, disable redirect following (followRedirect(false)) and handle redirects manually with origin validation.
ghsa CVSS3.1
6.8
Vulnerability type
CWE-200
Information Exposure
Published: 14 Apr 2026 · Updated: 14 Apr 2026 · First seen: 14 Apr 2026