NLTK 3.9.4 through 3.10.2 contains a path traversal vulnerability in CrubadanCorpusReader. _load_lang_ngrams joins the corpus root with crubadan_code, the column-0 value read from the corpus table.txt mapping file, and opens the result with the builtin open() rather than the pathsec-validated opener, so os.path.join discards the root when that value is absolute and the read escapes the corpus directory without the containment check nltk.pathsec applies when ENFORCE is set. An attacker who controls a corpus package can disclose file contents outside the corpus root through lang_freq, limited to paths ending in -3grams.txt whose contents parse as token count lines.

Attack Vector Local

Attack Complexity High

Privileges Required None

Attack Requirements Present

User Interaction Passive

Vulnerable System Confidentiality Impact Low

Vulnerable System Integrity Impact None

Vulnerable System Availability Impact None

Subsequent System Confidentiality Impact None

Subsequent System Integrity Impact None

Subsequent System Availability Impact None

Attack Vector Local

Attack Complexity High

Privileges Required None

Scope Unchanged

Confidentiality Impact Low

Integrity Impact None

Availability Impact None

User Interaction Required

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

No EPSS score available.

Key SSVC decision points have not yet been added.

Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).

Vendor Product Default status Versions
nltk nltk unaffected
Version Status Constraints
3.9.4 affected < 3.10.3
3.10.3 unaffected —

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Project Subscriptions

Vendors Products
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Advisories

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Fixes

Solution

No solution given by the vendor.

Workaround

No workaround given by the vendor.

References
Link Providers
https://github.com/nltk/nltk cve-icon
https://github.com/nltk/nltk/blob/v3.10.2/nltk/corpus/reader/crubadan.py#L90-L98 cve-icon
https://github.com/nltk/nltk/commit/10d34b3f4fe3fec74b76527a409eb0acbac2e8ab cve-icon
https://www.vulncheck.com/advisories/nltk-through-path-traversal-via-crubadancorpusreader-pathsec-bypass cve-icon
History

Sat, 22 Aug 2026 13:45:00 +0000

Type Values Removed Values Added
Description NLTK 3.9.4 through 3.10.2 contains a path traversal vulnerability in CrubadanCorpusReader. _load_lang_ngrams joins the corpus root with crubadan_code, the column-0 value read from the corpus table.txt mapping file, and opens the result with the builtin open() rather than the pathsec-validated opener, so os.path.join discards the root when that value is absolute and the read escapes the corpus directory without the containment check nltk.pathsec applies when ENFORCE is set. An attacker who controls a corpus package can disclose file contents outside the corpus root through lang_freq, limited to paths ending in -3grams.txt whose contents parse as token count lines.
Title NLTK 3.9.4 through 3.10.2 Path Traversal via CrubadanCorpusReader pathsec Bypass
First Time appeared Nltk
Nltk nltk
Weaknesses CWE-22
CPEs cpe:2.3:a:nltk:nltk:*:*:*:*:*:*:*:*
Vendors & Products Nltk
Nltk nltk
References
Metrics cvssV3_1

{'score': 2.5, 'vector': 'CVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:U/C:L/I:N/A:N'}

cvssV4_0

{'score': 2, 'vector': 'CVSS:4.0/AV:L/AC:H/AT:P/PR:N/UI:P/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N'}

Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: VulnCheck

Published:

Updated: 2026-08-22T13:34:08.493Z

Reserved: 2026-08-06T20:42:17.835Z

Link: CVE-2026-71514

cve-icon Vulnrichment

No data.

cve-icon NVD

No data.

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

No data.

Weaknesses