CVE-2026-93566: Io.netty/netty-codec-http: netty: http request smuggling due to control characters in the chunk-size line

Severity: medium (CVSS 6.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.5% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-09-18 · updated 2026-10-15
Weakness: CWE-1035

Description

A flaw was found in Netty. A remote attacker could exploit this by sending a specially crafted HTTP request that includes control characters within the chunk-size line. This bypasses the intended strict validation, allowing the attacker to inject arbitrary HTTP requests. This vulnerability can lead to HTTP request smuggling, potentially resulting in information disclosure or other unauthorized actions.

Affected products

Red Hat build of Keycloak 26.4: all versions
Red Hat AMQ Broker 7: all versions
Red Hat AMQ Clients: all versions
Red Hat build of Apache Camel 4 for Quarkus 3: all versions
Red Hat build of Apache Camel for Spring Boot 4: all versions
Red Hat build of Apicurio Registry 3: all versions
Red Hat Data Grid 8: all versions
Red Hat JBoss Enterprise Application Platform 8: all versions

References

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