CVE-2026-14180 — Undertow-core: undertow:http request smuggling via oversized chunk-size bit overlap
A flaw was found in the ChunkReader component of the Undertow HTTP server, which is used by WildFly and JBoss EAP to handle chunked transfer encoding. The issue occurs because t…
Published: 2026-08-11 · CVSS: 5.3 · CVSS 3.1
A flaw was found in the ChunkReader component of the Undertow HTTP server, which is used by WildFly and JBoss EAP to handle chunked transfer encoding. The issue occurs because the parser uses a single internal variable to store both the remaining chunk size and state flags. By sending a specially crafted request with an extremely large chunk size, an attacker can cause these values to overlap, tricking the parser into thinking a request has finished prematurely. This can allow a second, "smuggled" request to be processed out of sync, potentially bypassing security controls.
Source: CVE Program · Revision 8b16575c39f1e1810c5e863010da073d2d3285e7