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TI-2026-71723 Aliases CVE-2026-109956GHSA-9fgx-q9j8-3j83

Path traversal in NLTK WekaClassifier model paths

Priority HIGH 69CWE-22Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Attack requirements
Present
Impact type
—
Confidentiality · integrity · availability
Low · High · Low
Fix status
Partial Red Hat: 1 fixed, 4 without a fix

Attack profile from CVSS 4.0 · CNA. Fix status from CNA and Red Hat.

Summary

NLTK through 3.10.3 contains a path traversal flaw in WekaClassifier (CWE-22) where model paths are not validated. Attackers who control the model_filename or model argument can bypass nltk.pathsec containment and make the weka JVM write files or probe files outside allowed data roots. An unauthenticated remote attacker can trigger this.

Written with Claude Haiku 5.5 from the sources below · 2026-10-30

Description from the CNA

NLTK through 3.10.3 contains a path traversal vulnerability in WekaClassifier that allows attackers to bypass nltk.pathsec containment by supplying unvalidated model paths. Attackers controlling the model_filename or model argument can make the weka JVM write files via -d or probe files via -l outside allowed data roots.

Why it matters now

Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.00318 24th percentileScored 2026-11-07
Fix Partial Red Hat: 1 advisoryRed Hat: 1 fixed, 4 without a fix

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
Poc
Automatable
No
Technical impact
Partial

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

Affected products

VendorProductAffected versionsFixed inStatusSource
nltknltkup to 3.10.3—No fix listedCNA
  • nltk Vendornltk Affected up to 3.10.3 Fixed in — No fix listed CNA

CPE names Threatist (inferred) · 1

Inferred from how NVD named this product before; not given by a source.

CPEVersionsRoleVendor
cpe:2.3:a:nltk:nltk:*:*:*:*:*:*:*:*——nltk
  • cpe:2.3:a:nltk:nltk:*:*:*:*:*:*:*:* Versions — — ·nltk

Remediation

Red Hat fixed Red Hat OpenShift AI 3.4 in RHSA-2026:92510, released 2026-10-29. Red Hat lists Lightspeed Core, OpenShift Lightspeed and Red Hat OpenShift AI (RHOAI) with no fix available, and Red Hat Ansible Automation Platform 2 with no fix planned. The sources list no fixed version for nltk.

Written with Claude Haiku 5.5 from the sources below · 2026-10-30

Red Hat 1 advisory

  • RHSA-2026:92510 Released 2026-10-29 · Red Hat rating Critical
    RHOAI 3.4.6 - Red Hat OpenShift AI
    • Red Hat OpenShift AI 3.4 registry.redhat.io/rhoai/odh-built-in-detector-rhel9, registry.redhat.io/rhoai/odh-cli-rhel9, registry.redhat.io/rhoai/odh-dashboard-rhel9 +47

Vendor assessments

Red Hat

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

ProductStatusPlan or fix
Lightspeed CoreAffectedNo fix yet
OpenShift LightspeedAffectedNo fix yet
Red Hat Ansible Automation Platform 2AffectedNo fix planned: Out of support scope
Red Hat OpenShift AI (RHOAI)AffectedNo fix yet
Red Hat OpenShift AI 3.4Fixed RHSA-2026:92510
Not affected: 1 product
  • Red Hat OpenShift AI 3.4

Timeline

  1. 2026-10-13 Threatist record created from CVE-2026-109956
  2. 2026-10-13 Alias added: GHSA-9fgx-q9j8-3j83
  3. 2026-10-14 Priority changed: MEDIUM → LOW
  4. 2026-10-15 Affected versions changed · Red Hat
  5. 2026-10-15 CVSS score added · Red Hat
  6. 2026-10-26 CISA SSVC decision points changed
  7. 2026-10-26 Priority changed: LOW → HIGH
  8. 2026-10-30 Fix available: RHSA-2026:92510 · Red Hat
  9. 2026-10-30 Fix available: Red Hat OpenShift AI 3.4 · Red Hat

References

Advisory 1

  • 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 46 →

Sources

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