CVE-2026-58500
MCP Appium: Unescaped Locator Data XSS in MCP-UI Resource (createLocatorGeneratorUI)
Description
MCP Appium is an MCP server that provides AI assistants with tools to automate mobile app testing on Android and iOS. In versions prior to 1.85.10, the createLocatorGeneratorUI function interpolates attacker-controlled element attributes — text, content-desc, resource-id, and locator selector values — directly into an HTML template literal without any HTML or JavaScript context escaping. An attacker who controls the UI of the app under test can inject arbitrary HTML and JavaScript into the MCP UI resource returned by the generate_locators tool. When a victim's MCP client renders this resource, the injected script executes and can invoke arbitrary MCP tools via window.parent.postMessage, leading to unauthorized MCP tool execution such as taking screenshots, reading page source, or any other registered capability. This issue has been fixed in version 1.85.10.
INFO
Published Date :
July 13, 2026, 10:16 p.m.
Last Modified :
Aug. 26, 2026, 7:28 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | |||||
| CVSS 3.1 | HIGH | [email protected] | ||||
| CVSS 3.1 | HIGH | MITRE-CVE |
Solution
- Update MCP Appium to version 1.85.10.
- Apply vendor patches for MCP Appium.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-58500.
| URL | Resource |
|---|---|
| https://github.com/appium/appium-mcp/commit/e222bbbd6fe2b656a320efcd143563f08061a83d | Patch |
| https://github.com/appium/appium-mcp/security/advisories/GHSA-x975-rgx4-5fh4 | Exploit Vendor Advisory |
| https://github.com/appium/appium-mcp/security/advisories/GHSA-x975-rgx4-5fh4 | Exploit Vendor Advisory |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-58500 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-58500
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-58500 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-58500 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
Initial Analysis by [email protected]
Aug. 26, 2026
Action Type Old Value New Value Added CPE Configuration OR *cpe:2.3:a:appium:appium-mcp:*:*:*:*:*:node.js:*:* versions up to (including) 1.85.9 Added Reference Type GitHub, Inc.: https://github.com/appium/appium-mcp/commit/e222bbbd6fe2b656a320efcd143563f08061a83d Types: Patch Added Reference Type GitHub, Inc.: https://github.com/appium/appium-mcp/security/advisories/GHSA-x975-rgx4-5fh4 Types: Exploit, Vendor Advisory Added Reference Type CISA-ADP: https://github.com/appium/appium-mcp/security/advisories/GHSA-x975-rgx4-5fh4 Types: Exploit, Vendor Advisory -
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Jul. 14, 2026
Action Type Old Value New Value Added Reference https://github.com/appium/appium-mcp/security/advisories/GHSA-x975-rgx4-5fh4 Added SSVC {'id': 'CVE-2026-58500', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'poc'}, {'automatable': 'no'}, {'technicalImpact': 'partial'}], 'version': '2.0.3', 'timestamp': '2026-07-14T14:24:41.518699Z'} -
New CVE Received by [email protected]
Jul. 13, 2026
Action Type Old Value New Value Added Affected [{'vendor': 'appium', 'product': 'appium-mcp', 'versions': [{'status': 'affected', 'version': '< 1.85.10'}]}] Added Description MCP Appium is an MCP server that provides AI assistants with tools to automate mobile app testing on Android and iOS. In versions prior to 1.85.10, the createLocatorGeneratorUI function interpolates attacker-controlled element attributes — text, content-desc, resource-id, and locator selector values — directly into an HTML template literal without any HTML or JavaScript context escaping. An attacker who controls the UI of the app under test can inject arbitrary HTML and JavaScript into the MCP UI resource returned by the generate_locators tool. When a victim's MCP client renders this resource, the injected script executes and can invoke arbitrary MCP tools via window.parent.postMessage, leading to unauthorized MCP tool execution such as taking screenshots, reading page source, or any other registered capability. This issue has been fixed in version 1.85.10. Added CVSS V3.1 AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:H/A:N Added CWE CWE-79 Added Reference https://github.com/appium/appium-mcp/commit/e222bbbd6fe2b656a320efcd143563f08061a83d Added Reference https://github.com/appium/appium-mcp/security/advisories/GHSA-x975-rgx4-5fh4