# CWE-470: Use of Externally-Controlled Input to Select Classes or Code ('Unsafe Reflection') **KEV-linked** > As of 2026-10-14, CWE-470 (Unsafe Reflection) underlies 3 CVEs tracked by Threadlinqs, 1 of them in the CISA Known Exploited Vulnerabilities catalog, and is cited by 9 tracked threats. **Last updated:** 2026-10-14 ## What is CWE-470? The product uses external input with reflection to select which classes or code to use, but it does not sufficiently prevent the input from selecting improper classes or code. If the product uses external inputs to determine which class to instantiate or which method to invoke, then an attacker could supply values to select unexpected classes or methods. If this occurs, then the attacker could create control flow paths that were not intended by the developer. These paths could bypass authentication or access control checks, or otherwise cause the product to behave in an unexpected manner. This situation becomes a doomsday scenario if the attacker can upload files into a location that appears on the product's classpath (CWE-427) or add new entries to the product's classpath (CWE-426). Under either of these conditions, the attacker can use reflection to introduce new, malicious behavior into the product. CWE-470 is a base-level weakness in MITRE’s Common Weakness Enumeration. Applicable platforms: Java; PHP; Interpreted. _Source: [MITRE CWE](https://cwe.mitre.org/data/definitions/470.html) (CWE-470 definition, reproduced verbatim). Counts and linkage below are Threadlinqs data._ ## Consequences - **Integrity, Confidentiality, Availability, Other** — Execute Unauthorized Code or Commands, Alter Execution Logic. The attacker might be able to execute code that is not directly accessible to the attacker. Alternately, the attacker could call unexpected code in the wrong place or the wrong time, possibly modifying critical system state. - **Availability, Other** — DoS: Crash, Exit, or Restart, Other. The attacker might be able to use reflection to call the wrong code, possibly with unexpected arguments that violate the API (CWE-227). This could cause the product to exit or hang. - **Confidentiality** — Read Application Data. By causing the wrong code to be invoked, the attacker might be able to trigger a runtime error that leaks sensitive information in the error message, such as CWE-536. _Source: MITRE CWE, common consequences._ ## How CWE-470 is exploited in the wild Threadlinqs maps 3 CVEs to CWE-470, published between 2026-07-22 and 2026-09-16. 1 is listed in CISA’s Known Exploited Vulnerabilities catalog, the authoritative record of exploitation in the wild. By CVSS v3 severity the set splits into 1 critical, 1 high. The highest EPSS score in the set is 63.5% (CVE-2026-82078), the modelled probability of exploitation in the next 30 days. 9 tracked threats reference CWE-470 directly or through a CVE it covers; the most recent is “September 2026 CVE Landscape: 94 high-impact vulnerabilities, NetScaler zero-days CVE-2026-88771/CVE-2026-88772, AI-agent-assisted exploitation” (2026-10-14). Affected products concentrate in PaperCut (1), Progress Software (1), djust-org (1). ## Vulnerabilities (CVEs) All 3 CVEs mapped to CWE-470, CISA KEV first, then by CVSS score. - [CVE-2026-82078](https://intel.threadlinqs.com/cve/CVE-2026-82078) — CISA KEV · CVSS 9.1 critical · EPSS 63.5% · published 2026-08-28 - [CVE-2026-13181](https://intel.threadlinqs.com/cve/CVE-2026-13181) — CVSS 8.1 high · EPSS 0.5% · published 2026-07-22 - [CVE-2026-61599](https://intel.threadlinqs.com/cve/CVE-2026-61599) — published 2026-09-16 ## Affected vendors - [PaperCut](https://intel.threadlinqs.com/vendors/papercut) — 1 CVE - [Progress Software](https://intel.threadlinqs.com/vendors/progress-software) — 1 CVE - **djust-org** — 1 CVE ## Threat activity 9 tracked threats cite CWE-470: - [September 2026 CVE Landscape: 94 high-impact vulnerabilities, NetScaler zero-days CVE-2026-88771/CVE-2026-88772, AI-agent-assisted exploitation](https://intel.threadlinqs.com/threat/TL-2026-3448) — CRITICAL · 2026-10-14 - [Telerik UI for ASP.NET AJAX — Padding Oracle Chained to Unauthenticated Deserialization RCE (CVE-2026-13181–13184)](https://intel.threadlinqs.com/threat/TL-2026-2369) — HIGH · 2026-09-07 - [PaperCut NG/MF Chained Zero-Day RCE (CVE-2026-82078 & CVE-2026-81578) Under Active Exploitation](https://intel.threadlinqs.com/threat/TL-2026-2184) — CRITICAL · 2026-08-28 - [CosmosEscape: Platform-Wide Cosmos Master Key Exposure via Gremlin API Sandbox Escape in Azure Cosmos DB](https://intel.threadlinqs.com/threat/TL-2026-1784) — CRITICAL · 2026-07-31 - [CosmosEscape: Gremlin API Sandbox Escape Exposed Platform-Wide Key for Every Azure Cosmos DB Database](https://intel.threadlinqs.com/threat/TL-2026-1802) — CRITICAL · 2026-07-31 - [CosmosEscape: Azure Cosmos DB Gremlin Sandbox Escape Exposed Platform-Wide Master Key (CVE-2026-66803)](https://intel.threadlinqs.com/threat/TL-2026-1779) — CRITICAL · 2026-07-30 - [Apache Syncope Patches 12 CVEs Including Groovy Sandbox Bypass RCE and Audit Search SQLi](https://intel.threadlinqs.com/threat/TL-2026-1666) — CRITICAL · 2026-07-24 - [Fastjson 1.2.x Gadget-Free Remote Code Execution via @JSONType Remote Class Load (Versions 1.2.68-1.2.83)](https://intel.threadlinqs.com/threat/TL-2026-1599) — CRITICAL · 2026-07-21 - [Apache ActiveMQ OpenWire Deserialization RCE (CVE-2023-46604) — 6,400 Brokers Actively Exploited by HelloKitty, Kinsing, TellYouThePass and Andariel (Lazarus)](https://intel.threadlinqs.com/threat/TL-2026-0404) — CRITICAL · 2026-04-21 ## Mitigations - **Architecture and Design**: Refactor your code to avoid using reflection. - **Architecture and Design**: Do not use user-controlled inputs to select and load classes or code. - **Implementation**: Apply strict input validation by using allowlists or indirect selection to ensure that the user is only selecting allowable classes or code. _Source: MITRE CWE, potential mitigations._ ## Detection methods (MITRE CWE) - **Automated Static Analysis**: Automated static analysis, commonly referred to as Static Application Security Testing (SAST), can find some instances of this weakness by analyzing source code (or binary/compiled code) without having to execute it. Typically, this is done by building a model of data flow and control flow, then searching for potentially-vulnerable patterns that connect "sources" (origins of input) with "sinks" (destinations where the data interacts with external components, a lower layer such as the OS, etc.) _Source: MITRE CWE, detection methods. Threadlinqs detection rules for the threats above are Blue tier and higher._ ## Related weaknesses - [CWE-913 Improper Control of Dynamically-Managed Code Resources](https://intel.threadlinqs.com/cwe/CWE-913) - [CWE-610](https://cwe.mitre.org/data/definitions/610.html) - [CWE-20 Improper Input Validation](https://intel.threadlinqs.com/cwe/CWE-20) Canonical: https://intel.threadlinqs.com/cwe/CWE-470 Source definition: https://cwe.mitre.org/data/definitions/470.html Detection rules and IOCs for threats exploiting CWE-470 via the Threadlinqs MCP server (Purple tier): https://intel.threadlinqs.com/mcp