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TI-2025-43522 Aliases CVE-2025-71408GHSA-848c-c2cx-j7qx

NLTK < 3.9.3 Eval Injection via collocations.py Command-Line Arguments

Priority HIGH 72CWE-95Published · Updated

Key facts

Attack vector
Local
Privileges required
Low
User interaction
None
Attack complexity
Low
Attack requirements
None
Impact type
Code execution
Confidentiality · integrity · availability
High · High · High
Fix status
Partial Red Hat: 1 fixed, 3 without a fix

Attack profile from CVSS 4.0 · CNA. Fix status from CNA, GitHub and Red Hat. Impact type from CWE-95.

Summary

NLTK (Natural Language Toolkit) before version 3.9.3 contains an eval injection vulnerability in the nltk.collocations module that allows an attacker who controls command-line arguments to execute arbitrary Python code. When collocations.py is invoked directly, the __main__ block passes command-line arguments directly to eval() as suffixes of BigramAssocMeasures without allowlist validation or sanitization, enabling an attacker to supply a Python expression that escapes the intended attribute lookup and executes arbitrary code including OS commands via the os module.

Why it matters now

Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.00265 18th percentileScored 2026-11-07
Public exploit Yes 1 exploit referenceTagged by the CNA and NVD
Fix Partial ntlk (ntlk): 3.9.3nltk (PyPI): 3.9.3Red Hat: 1 advisoryRed Hat: 1 fixed, 3 without a fix

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
Poc
Automatable
No
Technical impact
Total

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
ntlkntlkbefore 3.9.33.9.3Patch availableCNA
—nltk (PyPI)before 3.9.33.9.3Patch availableGHSA-848c-c2cx-j7qx
  • ntlk Vendorntlk Affected before 3.9.3 Fixed in 3.9.3 Patch available CNA
  • nltk (PyPI) Vendor— Affected before 3.9.3 Fixed in 3.9.3 Patch available GHSA-848c-c2cx-j7qx

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:nltk:nltk:*:*:*:*:*:*:*:*before 3.9.3Vulnerablenltk
  • cpe:2.3:a:nltk:nltk:*:*:*:*:*:*:*:* Versions before 3.9.3 Vulnerable ·nltk

Remediation

  • Fix · CNA ntlk (ntlk) Fixed in 3.9.3
  • Fix · GHSA-848c-c2cx-j7qx nltk (PyPI) Fixed in 3.9.3 Advisory →

Red Hat 1 advisory

  • RHSA-2026:73987 Released 2026-09-30 · Red Hat rating Critical
    RHOAI 3.3.7 - Red Hat OpenShift AI
    • Red Hat OpenShift AI 3.3 registry.redhat.io/rhoai/odh-built-in-detector-rhel9, registry.redhat.io/rhoai/odh-dashboard-rhel9, registry.redhat.io/rhoai/odh-data-science-pipelines-argo-argoexec-rhel9 +47

Vendor assessments

Red Hat

Red Hat rating: Important. Red Hat's page for this CVE →

ProductStatusPlan or fix
Exploit IntelligenceAffectedNo fix planned: Will not fix
Red Hat Ansible Automation Platform 2AffectedNo fix planned: Will not fix
Red Hat OpenShift AI (RHOAI)AffectedNo fix yet
Red Hat OpenShift AI 3.3Fixed RHSA-2026:73987
Not affected: 4 products
  • Lightspeed Core
  • OpenShift Lightspeed
  • Red Hat OpenShift AI (RHOAI)
  • Red Hat OpenShift AI 3.3

Timeline

  1. 2026-10-02 Threatist record created from CVE-2025-71408
  2. 2026-10-03 Alias added: GHSA-848c-c2cx-j7qx
  3. 2026-10-07 Fix available: RHSA-2026:73987 · Red Hat

References

Exploit 1

Patch 3

Advisory 1

Other 3

  • TI-2026-00629 Arbitrary Code Execution in NLTK StanfordSegmenter via Untrusted JAR Loading CVSS 3.0CRITICAL 10.0
  • TI-2025-12800 Zip Slip Vulnerability in nltk/nltk Leading to Remote Code Execution CVSS 3.0CRITICAL 10.0
  • TI-2026-55173 NLTK before 3.10.3 JVM Argument Injection via Per-Call Options CVSS 4.0CRITICAL 9.3
  • TI-2026-55155 NLTK before 3.10.3 Remote Code Execution via Unsafe Pickle Deserialization CVSS 4.0CRITICAL 9.3
  • TI-2026-56370 nltk PorterStemmer before 3.10.3 Quadratic-time DoS CVSS 4.0HIGH 8.7
  • TI-2026-55172 NLTK 3.10.2 Path Traversal via corpus-reader constructors CVSS 4.0HIGH 8.8
See all 41 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences