CVE-2026-33870: Netty: HTTP Request Smuggling via Chunked Extension Quoted-String Parsing

March 26, 2026 (updated March 27, 2026)

Netty incorrectly parses quoted strings in HTTP/1.1 chunked transfer encoding extension values, enabling request smuggling attacks.

References

github.com/advisories/GHSA-pwqr-wmgm-9rr8
github.com/netty/netty
github.com/netty/netty/security/advisories/GHSA-pwqr-wmgm-9rr8
nvd.nist.gov/vuln/detail/CVE-2026-33870
w4ke.info/2025/06/18/funky-chunks.html
w4ke.info/2025/10/29/funky-chunks-2.html
www.rfc-editor.org/rfc/rfc9110

Code Behaviors & Features

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