---
id: "CVE-2026-2102"
kind: "vulnerability"
aliases: ["CVE-2026-2102"]
title: "wrensec-commons CREST: reflected XSS via _mimeType parameter in HTTP binding"
severity: "medium"
cvss: 6.1
epss: null
exploited: false
status: "open"
category: "package"
products: []
ecosystems: []
tags: ["crest", "java", "package", "web-apps", "wrensec-commons"]
not_affected_if: ["no-http-binding", "non-browser-clients"]
published_at: "2026-11-02T16:17:40+00:00"
first_seen_at: "2026-11-02T16:24:04+00:00"
updated_at: "2026-11-02T16:26:45+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-2102", "first_seen_at": "2026-11-02T16:24:04+00:00"}]
---

# wrensec-commons CREST: reflected XSS via _mimeType parameter in HTTP binding

The CREST framework's HTTP binding copies the _mimeType request parameter into the Content-Type response header without sanitizing it, so a JSON response can be served as HTML. An attacker who gets a user to open a crafted URL can run arbitrary JavaScript in that user's browser.

_Summary, check and fix written by a model from the sources; labelled as such._

## How to check

- Find the CREST version in your build file or dependency tree and check whether it is below `22.6.2` on the 22.x line or below `23.0.0` on the 23.x line.
- Confirm whether the application exposes CREST HTTP endpoints.

## Fix

- Upgrade to `22.6.2` on the 22.x line or `23.0.0` on the 23.x line.

## Timeline

- 2026-11-02T16:24:04+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-2102

## Documents

- [advisory] Vendor advisory: github.com https://github.com/WrenSecurity/wrensec-commons/security/advisories/GHSA-4vhv-49g2-496q
- [fix] Patch: github.com https://github.com/WrenSecurity/wrensec-commons/commit/5b50c64c14943b6f4d7faf996345e603956bae1d
- [fix] Patch: github.com https://github.com/WrenSecurity/wrensec-commons/commit/65bbfd8c63c42e84ff7699aa5b82a22c08a12624

## From the sources

wrensec-commons contains a reflected cross-site scripting (XSS) vulnerability in the CREST framework's HTTP binding. The HttpUtils.prepareResponse() method used the _mimeType request parameter to set the Content-Type response header without proper sanitization. By sending a GET request with _mimeType=text/html, an attacker could cause the browser to interpret a CREST JSON response as HTML, enabling execution of arbitrary JavaScript in the victim's browser. The vulnerability is exploitable by tricking a user into visiting a crafted URL targeting any deployed CREST endpoint. The issue is fixed in versions 22.6.2 and 23.0.0.

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