A flaw was found in Netty's netty-codec-http component. A remote attacker could exploit this vulnerability by sending a specially crafted HTTP/1.1 chunk-size token that includes post-digit whitespace. This incorrect parsing of the chunk size can lead to HTTP request smuggling. This allows an attacker to bypass security controls or access unauthorized resources in proxy/backend deployments.
See https://github.com/netty/netty/security/advisories/GHSA-j4mg-hqgv-34qc for fixed versions and remediation guidance.