Raw vector
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:NSummary
CVE-2025-6985 is a high-severity Improper Restriction of XML External Entity Reference (CWE-611) vulnerability. Its CVSS base score is 7.5 (High).
Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked at the 46th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.
This vulnerability is AI-related — categorised as NLP and Transformers; in the Privacy and Disclosure risk domain.
The strongest mitigations our analysis identified map to CM-6 (Configuration Settings) and SA-11 (Developer Testing and Evaluation) — see the control section below for these in your framework.
OWASP Top 10 for Web (2025)
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2025-31884
Vulnerability Data
The HTMLSectionSplitter class in langchain-text-splitters version 0.3.8 is vulnerable to XML External Entity (XXE) attacks due to unsafe XSLT parsing. This vulnerability arises because the class allows the use of arbitrary XSLT stylesheets, which are parsed using lxml.etree.parse() and lxml.etree.XSLT()…
more
without any hardening measures. In lxml versions up to 4.9.x, external entities are resolved by default, allowing attackers to read arbitrary local files or perform outbound HTTP(S) fetches. In lxml versions 5.0 and above, while entity expansion is disabled, the XSLT document() function can still read any URI unless XSLTAccessControl is applied. This vulnerability allows remote attackers to gain read-only access to any file the LangChain process can reach, including sensitive files such as SSH keys, environment files, source code, or cloud metadata. No authentication, special privileges, or user interaction are required, and the issue is exploitable in default deployments that enable custom XSLT.
- CWE(s)
AI Security AnalysisAI
- AI Category
- NLP and Transformers
- Risk Domain
- Privacy and Disclosure
- OWASP Top 10 for LLMs 2025
- None mapped
- Classification Reason
- Matched keywords: langchain
Related Threats
MITRE ATT&CK Enterprise Techniques
CVEs Like This One
Affected Assets
Mitigating Controls
Control response
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V1.5.1V15.3.2
Mitigating Controls (NIST 800-53 r5) AI
Secure configuration settings can disable external entity processing in XML parsers.
Developer testing can discover XXE flaws through targeted XML parsing tests.
Input validation can reject or sanitize XML containing external entity references.
Mitigating Controls (NIST CSF 2.0) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.
Hardened XML parser configurations directly disable external entity resolution.
Secure SDLC practices include input validation and safe XML parser configuration that prevent XXE.
Vulnerability scanning can discover XXE flaws but does not prevent their introduction in code.
Patching eliminates XXE-vulnerable parser versions but is only one aspect of software maintenance.
Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.
Security testing in development catches XXE via static analysis and dynamic XML fuzzing.
Vulnerability management identifies and patches XML libraries with unsafe default entity settings.
Secure development life cycle mandates input validation and entity handling that directly prevents XXE.
Application security requirements explicitly call for disabling external entity processing in XML parsers.
Secure architecture principles include safe parser configuration that mitigates external entity risks.
Secure coding standards require disabling DTDs and external entities in XML processing.