Executive brief
Netty is a widely used networking framework for Java applications. A vulnerability in its STOMP protocol component allows attackers to inject malicious headers into connection requests. This could enable an attacker to bypass authentication, escalate their privileges, or hijack connection parameters, depending on how the backend message broker is configured.
Technical details
The vulnerability exists in the 'StompSubframeEncoder' component of Netty's STOMP codec. While the STOMP 1.2 specification mandates that CONNECT and CONNECTED frames should not use standard header escaping for backward compatibility, Netty's implementation fails to perform validation to reject raw newline (\n) characters. An attacker who can control a header value (such as a login or passcode) can inject a raw newline followed by additional header fields. When the downstream broker parses the frame, it interprets these injected lines as legitimate headers. This can lead to authentication bypass or privilege escalation if the broker relies on specific headers for security decisions. The issue is resolved in versions 4.1.136.Final and 4.2.16.Final by adding validation to reject newlines in these frames.
Affected products
- Netty netty-codec-stomp < 4.1.136.Final, >= 4.2.0.Final, < 4.2.16.Final
Timeline
- 2026-07-14: advisory: GitHub Security Advisory published by maintainers
- 2026-07-29: disclosed: NVD publication date