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

> Attackers can smuggle HTTP requests via oversized chunk sizes in Undertow, bypassing security controls in WildFly and JBoss EAP.

- **Severity:** Medium 5.3 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 11 Aug 2026
- **Updated:** 20 Oct 2026
- **Also known as:** DEBIAN-CVE-2026-14180, GHSA-x562-68w7-4xvf, UBUNTU-CVE-2026-14180

## What is CVE-2026-14180?

CVE-2026-14180 is a medium-severity vulnerability in Red Hat Data Grid 8, published on 11 Aug 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### 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.

Weakness: CWE-444 (Inconsistent Interpretation of HTTP Requests)

## Which versions are affected by CVE-2026-14180?


## How do I fix CVE-2026-14180?

Apply the vendor's patch.

## Is CVE-2026-14180 being exploited?

There is no known exploitation of CVE-2026-14180 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-14180 and fix it if it is affected.

What it is: CVE-2026-14180 is a medium-severity vulnerability in Red Hat Data Grid 8, published on 11 Aug 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-14180 in the wild and no public exploit code.

Affected product: Red Hat Data Grid 8. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-14180/ (Markdown: https://insights.sbomify.com/CVE-2026-14180/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-14180
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-14180
- OSV: https://osv.dev/vulnerability/CVE-2026-14180

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-14180/
Summaries are generated and may contain mistakes; the official description above is the record.