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CVE-2026-126296 NLTK before 3.10.4 Path Traversal via save_maxent_params and load_maxent_params

6.3 mediumEPSS 0.3%

Medium (6.3) in nltk nltk. EPSS 0.3% estimated probability of exploitation activity in the next 30 days.

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NLTK before 3.10.4 contains a path traversal vulnerability in save_maxent_params() and load_maxent_params() that bypasses the pathsec filesystem restriction mechanism. Attackers who control the tab_dir argument can read or overwrite model parameter files outside permitted data roots, because the functions call Python's built-in open() directly.

Severity

CVSS 4.0

6.3 medium
CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:N/VI:L/VA:L/SC:N/SI:N/SA:N

CVSS 3.1

4.8 medium
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:L
EPSS
0.3% estimated probability of exploitation activity in the next 30 days; 27th percentile. Scored 2026-11-13. A forecast for this CVE across the internet, not for your own systems.
CWE
CWE-73 External Control of File Name or Path
OWASP Top 10
A06:2025 Insecure Design
Published
Modified
Assigned by
VulnCheck (CNA)
NVD analysis
Awaiting analysis
Record from
the NVD, synced

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Affected

Versions

From the CNA's record in the CVE List.

ProductAffected
nltkbefore 3.10.4

Attack patterns (CAPEC)

  • CAPEC-13 Subverting Environment Variable Values Likelihood: High · Severity: Very High
  • CAPEC-64 Using Slashes and URL Encoding Combined to Bypass Validation Logic Likelihood: High · Severity: High
  • CAPEC-72 URL Encoding Likelihood: High · Severity: High
  • CAPEC-76 Manipulating Web Input to File System Calls Likelihood: High · Severity: Very High
  • CAPEC-78 Using Escaped Slashes in Alternate Encoding Likelihood: High · Severity: High
  • CAPEC-79 Using Slashes in Alternate Encoding Likelihood: High · Severity: High
  • CAPEC-80 Using UTF-8 Encoding to Bypass Validation Logic Likelihood: High · Severity: High
  • CAPEC-267 Leverage Alternate Encoding Likelihood: High · Severity: High

The attack patterns MITRE's CAPEC relates to this record's weaknesses, as MITRE names them. Credits.

References

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