Raw vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:NSummary
CVE-2026-0846 is a high-severity Absolute Path Traversal (CWE-36) vulnerability in Nltk Nltk. 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 35th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.
This vulnerability is AI-related — categorised as NLP Libraries; in the Privacy and Disclosure risk domain.
The strongest mitigations our analysis identified map to AC-3 (Access Enforcement) and SI-10 (Information Input Validation) — see the control section below for these in your framework.
Deeper analysis AI-assisted summary
Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.
CVE-2026-0846 is a path traversal vulnerability (CWE-36) in the `filestring()` function of the `nltk.util` module in NLTK version 3.9.2. The function directly opens files specified by user input without proper path sanitization, enabling arbitrary file reads on the system hosting the affected software. This flaw affects applications using NLTK 3.9.2 that invoke `filestring()` with unsanitized inputs.
The vulnerability carries a CVSS v3.1 base score of 7.5 (AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N), allowing unauthenticated remote attackers to exploit it over the network with low complexity and no user interaction. Exploitation is feasible in scenarios where the function processes user-supplied paths, such as web APIs or other interfaces, granting attackers read access to sensitive system files via absolute paths or directory traversals.
Advisories on Huntr.com (https://huntr.com/bounties/007b84f8-418e-4300-99d0-bf504c2f97eb) provide details on the issue through a reported bounty.
NLTK, a Python library for natural language processing, has relevance to AI/ML workflows where vulnerable code may be deployed in data processing pipelines.
OWASP Top 10 for Web (2025)
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-10350
Vulnerability Data
A vulnerability in the `filestring()` function of the `nltk.util` module in nltk version 3.9.2 allows arbitrary file read due to improper validation of input paths. The function directly opens files specified by user input without sanitization, enabling attackers to access…
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sensitive system files by providing absolute paths or traversal paths. This vulnerability can be exploited locally or remotely, particularly in scenarios where the function is used in web APIs or other interfaces that accept user-supplied input.
- CWE(s)
AI Security AnalysisAI
- AI Category
- NLP Libraries
- Risk Domain
- Privacy and Disclosure
- OWASP Top 10 for LLMs 2025
- None mapped
- Classification Reason
- Matched keywords: nltk
Related Threats
MITRE ATT&CK Enterprise Techniques
CVEs Like This One
Affected Assets
Mitigating Controls
Control response
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V5.3.2
Mitigating Controls (NIST 800-53 r5) AI
Enforces the intended directory access authorizations that path traversal would otherwise bypass.
Input validation directly stops construction of absolute paths from untrusted data before they reach file operations.
Least privilege reduces the impact of any unauthorized file access obtained via traversal.
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.
Secure SDLC practices directly require input validation and path sanitization that prevent absolute path traversal.
Patching/maintenance can remediate known path-traversal flaws in deployed software (partial prevention of exploitability) but does nothing to stop the coding defect from being introduced in the first place.
PR.AA-05 defines and reviews access policies but does not address code-level pathname neutralization, so neither direction prevents CWE-22.
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 can detect absolute path traversal via static analysis and fuzzing.
Secure development lifecycle includes input validation and path-handling requirements that reduce absolute path traversal risk.
Application security requirements typically mandate controls against path traversal in file-access functions.
Secure architecture principles call for canonicalization and sandboxing that limit absolute path traversal.
Secure coding standards directly require neutralization of absolute path sequences in pathname construction.
Information access restriction limits which files can be reached but does not address the path-construction flaw itself.