AsyncHttpClient leaks authorization credentials to untrusted domains on cross-origin redirectsGHSA-cmxv-58fp-fm3g
MEDIUMFix: AsyncHttpClient/async-http-client@6b2fbb7GHSA-cmxv-58fp-fm3g is a medium-severity (CVSS 6.8) Information Exposure vulnerability in org.asynchttpclient:async-http-client. A fix is available for org.asynchttpclient:async-http-client — see the affected versions and patch details below.
Exploitation Status
No confirmed exploitation observed yet
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for GHSA-cmxv-58fp-fm3g.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
Where this sits among everything scored
Real-World Exposure
org.asynchttpclient:async-http-client☕org.asynchttpclient:async-http-clientReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Maven packages — download data is not available via public APIs for these ecosystems.
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 or 2.14.5. 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 or 2.14.5 because the Realm bypass still re-generates credentials.
Alternatively, disable redirect following (followRedirect(false)) and handle redirects manually with origin validation.
References
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| ☕Maven | org.asynchttpclient:async-http-client | ≥ 3.0.0.Beta1&&< 3.0.9 | 3.0.9org.asynchttpclient:async-http-client:3.0.9 |
| ☕Maven | org.asynchttpclient:async-http-client | ≥ 2.0.0&&< 2.14.5 | 2.14.5org.asynchttpclient:async-http-client:2.14.5 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for org.asynchttpclient:async-http-client, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update org.asynchttpclient:async-http-client to 3.0.9 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-cmxv-58fp-fm3g is resolved across your whole dependency graph.
Workarounds
Stop reflecting attacker-controlled destinations: resolve every redirect target against an allowlist of paths or hosts you own, prefer a server-side key over a full URL in the request, and reject absolute URLs entirely where the flow only ever needs a relative one.
Frequently Asked Questions
Is GHSA-cmxv-58fp-fm3g in your dependencies?
Find it across Maven, including transitive dependencies.