Netty HTTP Request Smuggling via Chunk-Size Line Bypass
CVE-2026-93566 Published on September 18, 2026
Io.netty/netty-codec-http: netty: http request smuggling due to control characters in the chunk-size line
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.
Vulnerability Analysis
CVE-2026-93566 is exploitable with network access, and does not require authorization privileges or user interaction. This vulnerability is considered to have a low attack complexity. The potential impact of an exploit of this vulnerability is considered to have a small impact on confidentiality and integrity, and no impact on availability.
Timeline
Reported to Red Hat.
Made public.
Weakness Type
OWASP Top Ten 2017 Category A9 - Using Components with Known Vulnerabilities
Weaknesses in this category are related to the A9 category in the OWASP Top Ten 2017.
Products Associated with CVE-2026-93566
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