CVE-2025-6984 in LangChain
Summary
by MITRE • 09/04/2025
The langchain-ai/langchain project, specifically the EverNoteLoader component, is vulnerable to XML External Entity (XXE) attacks due to insecure XML parsing. The affected version is 0.3.63. The vulnerability arises from the use of etree.iterparse() without disabling external entity references, which can lead to sensitive information disclosure. An attacker could exploit this by crafting a malicious XML payload that references local files, potentially exposing sensitive data such as /etc/passwd.
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Analysis
by VulDB Data Team • 09/05/2025
The CVE-2025-6984 vulnerability resides within the langchain-ai/langchain project's EverNoteLoader component, representing a critical security flaw that exposes the system to XML External Entity attacks. This vulnerability specifically affects version 0.3.63 of the library and demonstrates a fundamental weakness in how XML documents are processed within the application's data ingestion pipeline. The flaw stems from the insecure use of Python's etree.iterparse() function, which by default permits external entity resolution without proper safeguards, creating an attack surface that can be exploited by malicious actors to access sensitive system resources.
The technical implementation of this vulnerability occurs through the improper handling of XML parsing operations within the EverNoteLoader module. When the component processes XML documents, it utilizes etree.iterparse() without explicitly disabling external entity references, which allows XML parsers to resolve external entities and access local file systems. This parsing behavior creates a pathway for attackers to construct malicious XML payloads that reference system files such as /etc/passwd, enabling unauthorized data disclosure. The vulnerability operates at the core of data processing workflows where untrusted XML content is parsed, making it particularly dangerous in environments where the application handles external data sources from potentially malicious origins.
From an operational impact perspective, this vulnerability presents significant risks to organizations utilizing the langchain framework for document processing and data ingestion tasks. An attacker exploiting this XXE vulnerability could gain access to sensitive system information, including but not limited to user credentials, configuration files, and system metadata that might be stored in local file paths. The potential for data exfiltration extends beyond simple file access to include broader system reconnaissance that could facilitate additional attacks. The vulnerability's impact is amplified when the application runs with elevated privileges or processes sensitive data, as the attacker could potentially access confidential information that should remain protected.
The vulnerability aligns with CWE-611 (Improper Restriction of XML External Entity Reference) and represents a classic example of insecure XML processing that violates fundamental security principles for handling untrusted data. This flaw also maps to ATT&CK technique T1566.002 (Phishing: Spearphishing Attachment) and T1071.004 (Application Layer Protocol: DNS) when considering how attackers might deliver malicious XML content through document attachments or network-based attacks. Organizations should implement immediate mitigations including updating to patched versions of the langchain library, disabling external entity resolution in XML parsers, and implementing proper input validation for all XML processing components. Additional protective measures should include network segmentation, monitoring for suspicious XML processing activities, and regular security assessments of third-party libraries to prevent similar vulnerabilities from emerging in other components of the application stack.