CVE-2026-93568: Io.netty/netty-codec-http2: io.netty/netty-codec-http3: netty: http/2 and http/3 extended connect requests are downgraded as regular connect requests

Severity: high (CVSS 7.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 1.0% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-09-18 · updated 2026-10-19
Weakness: CWE-20

Description

A flaw was found in Netty. A remote attacker could exploit this vulnerability by sending specially crafted HTTP/2 or HTTP/3 Extended CONNECT requests. Netty's HTTP-object conversion path incorrectly processes these requests as regular HTTP/1.1 CONNECT requests, leading to a loss of critical protocol and path information. This misinterpretation can allow attackers to bypass security policies, such as routing or authorization logic, in applications that rely on Netty for HTTP/2 or HTTP/3 communication, resulting in integrity loss.

Affected products

Red Hat build of Keycloak 26.4: all versions
Red Hat Build of Apache Camel 3.33.3.SP2: all versions — fixed in 4.1.138.Final-redhat-00001
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 Fuse 7: all versions
Red Hat JBoss Enterprise Application Platform 7: all versions
Red Hat JBoss Enterprise Application Platform Expansion Pack: all versions
Red Hat Single Sign-On 7: all versions

How to fix

Upgrade to a fixed version: Red Hat Build of Apache Camel 3.33.3.SP2 4.1.138.Final-redhat-00001. Check the vendor advisory for mitigations.

References

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