Vulnerability in netty

[ Why it matters ]Priority signals

• Public proof-of-concept exploit exists (CISA SSVC)

[ Description ]Official description

Netty is an asynchronous, event-driven network application framework. Prior to 4.2.13.Final and 4.1.133.Final, HttpContentDecompressor accepts a maxAllocation parameter to limit decompression buffer size and prevent decompression bomb attacks. This limit is correctly enforced for gzip and deflate encodings via ZlibDecoder, but is silently ignored when the content encoding is br (Brotli), zstd, or snappy. An attacker can bypass the configured decompression limit by sending a compressed payload with Content-Encoding: br instead of Content-Encoding: gzip, causing unbounded memory allocation and out-of-memory denial of service. The same vulnerability exists in DelegatingDecompressorFrameListener for HTTP/2 connections. This vulnerability is fixed in 4.2.13.Final and 4.1.133.Final.

[ Fixes ]Fixes and patches

No fix or interim patch is linked from our sources yet. Check the vendor references below and limit exposure of affected systems until a fix is available.

[ Advisories ]Government CERT advisories

• BSI CERT-Bund20 Oct 2026WID-SEC-2026-4062

  Oracle Utilities Applications: Multiple vulnerabilities Translated from German

  CVE-2026-49844CVE-2026-41239CVE-2026-68497+5 more CVEs
• BSI CERT-Bund20 Oct 2026WID-SEC-2026-4060

  Oracle NoSQL Database: Vulnerability threatens availability Translated from German

  CVE-2026-42587
• CERT-FR16 Oct 2026CERTFR-2026-AVI-1336

  Multiple vulnerabilities in IBM products Translated from French

  Multiple vulnerabilities have been discovered in IBM products. Some of them allow an attacker to cause remote arbitrary code execution, privilege escalation and remote denial of service.

  CVE-2026-14671CVE-2026-11548CVE-2022-22950+490 more CVEs

[ References ]References

• github.com/netty/netty/security/advisories/GHSA-f6hv-jmp6-3vwvx_refsource_CONFIRM