Vulnerability · Published Aug 11, 2026 · Assigned by redhat
CVE-2026-14180Undertow-core: undertow:http request smuggling via oversized chunk-size bit overlap
Medium 5.3
In plain English
A medium-severity security flaw in Red Hat JBoss Enterprise Application Platform 8.1.8.GA from Red Hat. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 1.0% (higher than 64% of all known vulnerabilities).
Official 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.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian:14 | undertow | no fix listed | DEBIAN-CVE-2026-14180 |
| Ubuntu:26.04:LTS | undertow | no fix listed | UBUNTU-CVE-2026-14180 |
| Ubuntu:26.10 | undertow | no fix listed | UBUNTU-CVE-2026-14180 |
Affected products (as reported)
Weakness: CWE-444 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
References
- RHSA-2026:70228 vendor-advisory, x_refsource_REDHAT
- RHSA-2026:70229 vendor-advisory, x_refsource_REDHAT
- RHSA-2026:70230 vendor-advisory, x_refsource_REDHAT
- RHSA-2026:70277 vendor-advisory, x_refsource_REDHAT
- https://access.redhat.com/security/cve/CVE-2026-14180 vdb-entry, x_refsource_REDHAT
- RHBZ#2494771 issue-tracking, x_refsource_REDHAT