CVE-2026-45300: AsyncHttpClient sensitive information leak in Redirect30xInterceptor

CVE-2026-45300 · Severity: high · CVSS 7.4 · Published 2026-06-05

The AsyncHttpClient (AHC) library, a popular tool for Java applications to handle web requests, contains a flaw that leaks sensitive user information. When an application is redirected from a trusted site to a different website, the library fails to remove security cookies from the request. This allows an attacker who controls a redirect destination to steal session cookies, login credentials, or API keys, potentially leading to account takeover or data theft.

Technologies: AsyncHttpClient, org.asynchttpclient:async-http-client (Maven). Vendors: AsyncHttpClient, Maven.

Quick answers

Is CVE-2026-45300 exploited in the wild?
No. Junglewise Threat Intelligence has no report of CVE-2026-45300 being exploited in the wild.
How severe is CVE-2026-45300?
High severity, with a CVSS score of 7.4, published 5 June 2026.
Which products and versions are affected?
AsyncHttpClient >= 2.0.0, < 2.15.0; >= 3.0.0.Beta1, < 3.0.10, >= 3.0.0.Beta1, < 3.0.10; >= 2.0.0, < 2.15.0; org.asynchttpclient:async-http-client (Maven) ECOSYSTEM:introduced=3.0.0.Beta1,fixed=3.0.10.
Is there a fix for CVE-2026-45300?
Yes. org.asynchttpclient:async-http-client (Maven): upgrade to 3.0.10 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-45300 attacked?
It is attacked over the network, in a software library.
Am I affected by CVE-2026-45300?
Check whether you run AsyncHttpClient or org.asynchttpclient:async-http-client (Maven) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

How to fix

  • org.asynchttpclient:async-http-client (Maven): upgrade to 3.0.10 or later
    # set org.asynchttpclient:async-http-client to 3.0.10 in your pom.xml or build.gradle

Technical details

A sensitive information disclosure vulnerability exists in AsyncHttpClient (AHC) due to improper header sanitization during HTTP redirects. The 'propagatedHeaders()' method in 'Redirect30xInterceptor.java' is designed to strip sensitive headers like 'Authorization' when a request is redirected to a different origin or downgraded from HTTPS to HTTP. However, it fails to remove the 'Cookie' header. An attacker can exploit this by inducing a redirect to a malicious domain, which will then receive the original site's session cookies. This vulnerability affects versions 2.x prior to 2.15.0 and 3.x prior to 3.0.10. Patches are available in versions 2.15.0 and 3.0.10.

Affected products

  • AsyncHttpClient AsyncHttpClient (AHC) >= 2.0.0, < 2.15.0; >= 3.0.0.Beta1, < 3.0.10

Identifiers

  • CVE-2026-45300
  • GHSA-fmxf-pm6p-7xgm

Timeline

  • 2026-05-12: patched: Versions 2.15.0 and 3.0.10 released
  • 2026-06-05: disclosed: CVE-2026-45300 published

References

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