CVE-2026-59900¶
WSO2 Products impacted: no
Customer action required: no
REPORTED VULNERABILITY¶
Netty's HTTP/2-to-HTTP/1.x translation layer (Http2StreamFrameToHttpObjectCodec and InboundHttp2ToHttpAdapter) fails to deduplicate or validate Host headers when an HTTP/2 client supplies both the :authority pseudo-header and a literal host header in a single HEADERS frame, producing an HttpRequest containing two Host headers with attacker-controlled differing values. Fixed in 4.1.136.Final and 4.2.16.Final.1
REPORTED PRODUCTS¶
- WSO2 Identity Server : 7.2.0
WSO2 JUSTIFICATION¶
A single Netty distribution reaches the runtime in WSO2 Identity Server, shipped as a WSO2 orbit bundle that re-wraps an upstream release within the affected range. The vulnerable class is therefore physically present, and this finding turns entirely on whether it is reachable.
The HTTP/2 translation layer is never used. Nothing in the shipped distribution references Http2StreamFrameToHttpObjectCodec or InboundHttp2ToHttpAdapter; these classes appear only inside the Netty bundle itself. Request smuggling through that translator requires a Netty HTTP/2 server translating to HTTP/1.x, which this product never builds.
No Netty HTTP server is ever started. io.netty.handler.codec.http.HttpServerCodec and io.netty.handler.codec.spdy.SpdyFrameCodec are referenced by nothing in the shipped distribution, so no Netty server pipeline is ever built. WSO2 Identity Server serves all inbound HTTP through embedded Apache Tomcat, configured in repository/conf/tomcat/catalina-server.xml.
Based on this evidence, we conclude that this vulnerability does not pose a security risk to the impacted versions of WSO2 products listed above.