CVE Catalog

CVE-2026-85721

HighCVSS 7.5
Published: Translated: NVD NIST

Summary

The AsyncHttpClient (AHC) library in versions from 2.0.0 until 2.16.1 and 3.0.12 installs the HTTP/1.1 response decompressor without a cumulative output-size limit. A hostile or compromised server can send a small gzip, deflate, or snappy response that expands across chunks until the client exhausts its heap and raises OutOfMemoryError. Brotli and zstd are also affected, and in versions 3.0.8 through 3.0.10 the HTTP/2 decompressor is unbounded as well.

Risk Assessment

An attacker can cause heap exhaustion and crash a Java application using AHC, resulting in denial of service. The risk is high because a controlled server response or in-transit modification is sufficient to trigger it.

Recommendation

Upgrade AsyncHttpClient to version 2.16.1 or 3.0.12, which enforce a total decompressed-byte limit for the whole response.

Other vulnerabilities in AsyncHttpClient

See all
Original NVD description (English source)

The AsyncHttpClient (AHC) library allows Java applications to easily execute HTTP requests and asynchronously process HTTP responses. From 2.0.0 until 2.16.1 and 3.0.12, automatic response decompression on the HTTP/1.1 path uses ChannelManager.newHttpContentDecompressor() to install Http1ContentDecompressor without a cumulative output-size limit. A hostile or compromised server, or an attacker who can alter a response in transit, can send a small gzip, deflate, or snappy response that expands across chunks until the client exhausts its heap and raises OutOfMemoryError; brotli and zstd are also affected when their optional codecs are present. In versions 3.0.8 through 3.0.10, the HTTP/2 decompressor is also unbounded, so switching protocols does not mitigate the issue on those releases. A limit applied to each decode call is insufficient because the response can be delivered as many small chunks, so the fixed implementation tracks total decompressed bytes for the whole response. This issue is fixed in versions 2.16.1 and 3.0.12.

Vulnerability data from NVD (NIST) · CISA KEV · EPSS