CVE-2026-58500Public exploitNetwork attack vector

MCP tool execution via unescaped locator attributes

Published Jul 13, 2026 · Updated Jul 13, 2026

Cross-site scripting in Appium MCP before 1.85.10 allows remote attackers to execute registered MCP tools through a rendered locator UI. The createLocatorGeneratorUI function places app-controlled text, content descriptions, resource IDs, strategies, and selectors into HTML and inline JavaScript without context escaping. Exploitation requires a victim MCP client to render generate_locators output from an attacker-controlled app; injected script can then request screenshots, page source, scripts, or other registered tool actions.

CVSS severity8.2
High
EPSS probability0.35%
Next 30 days · Sep 17, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Cross-site scripting in Appium MCP before 1.85.10 allows remote attackers to execute registered MCP tools through a rendered locator UI. The createLocatorGeneratorUI function places app-controlled text, content descriptions, resource IDs, strategies, and selectors into HTML and inline JavaScript without context escaping. Exploitation requires a victim MCP client to render generate_locators output from an attacker-controlled app; injected script can then request screenshots, page source, scripts, or other registered tool actions.

The record

CVE
CVE-2026-58500
Published
Jul 13, 2026
Updated
Jul 13, 2026
Vendor
Appium
Product
Appium MCP
Classifications
CWE-79, T1203
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jul 13, 2026CVE publishedPublication date reported by the CVE source.
  2. Jul 13, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=< 1.85.10

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Appium · Appium MCPversion=< 1.85.10

Published CVSS scores

8.2GitHubCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:H/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
T1203Exploitation for Client Execution

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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