Vulnerability · Published Jun 5, 2026 · Assigned by GitHub_M
CVE-2026-45300async-http-client: Cookie header not stripped on cross-origin redirect
High 7.4
In plain English
A high-severity information exposure in async-http-client from AsyncHttpClient. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 34% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
The AsyncHttpClient (AHC) library allows Java applications to easily execute HTTP requests and asynchronously process HTTP responses. Versions on the 2.x branch prior to 2.15.0 and the 3.x branch prior to 3.0.10 leak `Cookie` headers to cross-origin redirect targets. When following a redirect to a different origin, the `propagatedHeaders()` method in `Redirect30xInterceptor.java` strips `Authorization` and `Proxy-Authorization` headers but does not strip the `Cookie` header, causing session cookies and other sensitive cookie values to be sent to attacker-controlled servers. Versions 2.15.0 and 3.0.10 patch the issue.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian:12 | async-http-client | no fix listed | DEBIAN-CVE-2026-45300 |
| Maven | org.asynchttpclient:async-http-client | 3.0.10 | GHSA-fmxf-pm6p-7xgm |
| Maven | org.asynchttpclient:async-http-client | 2.15.0 | GHSA-fmxf-pm6p-7xgm |
| Ubuntu:22.04:LTS | async-http-client | no fix listed | UBUNTU-CVE-2026-45300 |
| Ubuntu:24.04:LTS | async-http-client | no fix listed | UBUNTU-CVE-2026-45300 |
| Ubuntu:25.10 | async-http-client | no fix listed | UBUNTU-CVE-2026-45300 |
| Ubuntu:26.04:LTS | async-http-client | no fix listed | UBUNTU-CVE-2026-45300 |
| Ubuntu:26.10 | async-http-client | no fix listed | UBUNTU-CVE-2026-45300 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| AsyncHttpClient | async-http-client | >= 3.0.0.Beta1, < 3.0.10>= 2.0.0, < 2.15.0 |
Weakness: CWE-200 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:N/A:N
References
- https://github.com/AsyncHttpClient/async-http-client/security/advisories/GHSA-fmxf-pm6p-7xgm x_refsource_CONFIRM
- https://github.com/AsyncHttpClient/async-http-client/commit/3b0e3e9e x_refsource_MISC
- https://github.com/AsyncHttpClient/async-http-client/releases/tag/async-http-client-project-3.0.10 x_refsource_MISC