CVE-2026-40490 — AsyncHttpClient leaks authorization credentials to untrusted domains on cross-origin redirects

Affected: AsyncHttpClient async-http-client

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-g…

GHSA-mj4r-2hfc-f8p6 — Netty Lz4FrameDecoder is vulnerable to resource exhaustion

Affected: Maven: io.netty:netty-codec-compression, Maven: io.netty:netty-codec

### Summary Lz4FrameDecoder allocates a ByteBuf of size `decompressedLength` (up to 32 MB per block) before LZ4 runs. A peer only needs a 21-byte header plus `compressedLength` payload bytes - 22 bytes if `compressedLength == 1` - to force that allocation.

### Details io.netty.handler.codec.compression.Lz4FrameDecoder#decode Header fields are trusted for sizing. On the compressed path, after `readableBytes >= compressedLength`, the decoder does `ctx.alloc().buffer(decompressedLength, decompressedLength)` then decompresses.

### PoC The test below demonstrates how an attacker sending 22 bytes will force the server to allocate 32MB

```java @Test void test() throws Exception { EventLoopGroup workerGroup = new MultiThreadIoEventLoopGroup(NioIoHandler.newFactory()); try { AtomicReference<Throwable> serverError = new AtomicReference<>(); CountDownLatch latch = new CountDownLatch(1);

ServerBootstrap server = new ServerBootstrap() .group(workerGroup) .channel(NioServerSocketChannel.class) .childHandler(new ChannelInitializer<SocketChannel>() { @Override protected void initChannel(SocketChannel ch) { ch.pipeline() .addLast(new Lz4FrameDecoder()) .addLast(new ChannelInboundHandlerAdapter() {…

Most recent entries from all

CVE-2026-40490 — AsyncHttpClient leaks authorization credentials to untrusted domains on cross-origin redirects

GHSA-mj4r-2hfc-f8p6 — Netty Lz4FrameDecoder is vulnerable to resource exhaustion