Improper Handling of Highly Compressed Data (Data Amplification) Affecting io.netty:netty-codec-http2 package, versions [,4.1.133.Final)[4.2.0.Alpha1,4.2.13.Final)
Threat Intelligence
Snyk has a proof-of-concept or detailed explanation of how to exploit this vulnerability.
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
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Test your applications- Snyk IDSNYK-JAVA-IONETTY-16438929
- published7 May 2026
- disclosed7 May 2026
- creditoffset
Introduced: 7 May 2026
NewCVE-2026-42587 (opens in a new tab)How to fix?
Upgrade io.netty:netty-codec-http2 to version 4.1.133.Final, 4.2.13.Final or higher.
Overview
io.netty:netty-codec-http2 is a HTTP2 sub package for the netty library, an event-driven asynchronous network application framework.
Affected versions of this package are vulnerable to Improper Handling of Highly Compressed Data (Data Amplification) in the HttpContentDecompressor and DelegatingDecompressorFrameListener components when the Content-Encoding header is set to br, zstd, or snappy. An attacker can exhaust system memory and cause a denial of service by sending a highly compressed payload that decompresses to a very large size, bypassing the configured decompression limit.