CVE-2026-93566 Io.netty/netty-codec-http: netty: http request smuggling due to control characters in the chunk-size line
Remote attackers can exploit HTTP request smuggling in Netty via control characters in chunk-size lines, leading to information disclosure or unauthorized actions.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-93566?
CVE-2026-93566 is a medium-severity vulnerability in Red Hat AMQ Broker 7, published on 18 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official 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.
Weakness: CWE-1035
Which versions are affected by CVE-2026-93566?
How do I fix CVE-2026-93566?
Upgrade to a fixed version.
Is CVE-2026-93566 being exploited?
There is no known exploitation of CVE-2026-93566 in the wild and no public exploit code.
Sources
Also known as DEBIAN-CVE-2026-93566, GHSA-9mrj-55p4-qwf4, UBUNTU-CVE-2026-93566.