CVE-2026-14180 Undertow-core: undertow:http request smuggling via oversized chunk-size bit overlap

Description

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.

Exploitable à distance par le réseau, sans compte et sans action d’un utilisateur ; l’impact sur les données ou le service reste limité.

Vecteur d’attaque

Réseau

Complexité

Faible

Privilèges requis

Aucun

Interaction

Aucune

Portée

Inchangée

Confidentialité

Aucun

Intégrité

Faible

Disponibilité

Aucun

Produits et versions touchés