NLTK through 3.10.3 Path Traversal via Model-Artifact APIs
Priority HIGH 69CWE-73Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- High
- Attack requirements
- Present
- Impact type
- —
- Confidentiality · integrity · availability
- High · Low · Low
- Fix status
- Partial Red Hat: 2 fixed, 5 without a fix
Attack profile from CVSS 4.0 · CNA. Fix status from CNA, GitHub and Red Hat.
Summary
NLTK through 3.10.3 contains a path traversal vulnerability in model-artifact APIs that bypass pathsec enforcement by using raw file operations on caller-controlled paths. Attackers can read or write files outside allowed sandbox roots through TransitionParser, AveragedPerceptron, PerceptronTagger, and maxent parameter APIs when pathsec is enabled.
Why it matters now
Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.00339 27th percentileScored 2026-11-07
Public exploit Yes 1 exploit referenceTagged by NVD
Fix Partial nltk (nltk): 3.10.4nltk (PyPI): 3.10.4Red Hat: 2 advisoriesRed Hat: 2 fixed, 5 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
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| nltk | nltk | up to 3.10.3 | 3.10.4 | Patch available | CNA |
| — | nltk (PyPI) | before 3.10.4 | 3.10.4 | Patch available | GHSA-8mgp-746c-j5xp |
- nltk Vendornltk Affected up to 3.10.3 Fixed in 3.10.4 Patch available CNA
- nltk (PyPI) Vendor— Affected before 3.10.4 Fixed in 3.10.4 Patch available GHSA-8mgp-746c-j5xp
Remediation
- Fix · CNA nltk (nltk) Fixed in 3.10.4
- Fix · GHSA-8mgp-746c-j5xp nltk (PyPI) Fixed in 3.10.4 Advisory →
Red Hat 2 advisories
- RHSA-2026:86891 Released 2026-10-21 · Red Hat rating CriticalRHOAI 3.5.2 - Red Hat OpenShift AI
- Red Hat OpenShift AI 3.5 registry.redhat.io/rhoai/odh-automl-rhel9, registry.redhat.io/rhoai/odh-built-in-detector-rhel9, registry.redhat.io/rhoai/odh-cli-rhel9 +47
- RHSA-2026:84734 Released 2026-10-19 · Red Hat rating CriticalRHOAI 3.4.5 - Red Hat OpenShift AI
- Red Hat OpenShift AI 3.4 registry.redhat.io/rhoai/odh-ai-gateway-payload-processing-rhel9, registry.redhat.io/rhoai/odh-automl-rhel9, registry.redhat.io/rhoai/odh-autorag-rhel9 +47
Vendor assessments
Red Hat
Red Hat rating: Important. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Exploit Intelligence | Affected | No fix planned: Will not fix |
| Lightspeed Core | Affected | No fix yet |
| OpenShift Lightspeed | Affected | No fix planned: Will not fix |
| Red Hat Ansible Automation Platform 2 | Affected | No fix planned: Will not fix |
| Red Hat OpenShift AI (RHOAI) | Affected | No fix yet |
| Red Hat OpenShift AI 3.4 | Fixed | RHSA-2026:84734 |
| Red Hat OpenShift AI 3.5 | Fixed | RHSA-2026:86891 |
Not affected: 3 products
- OpenShift Lightspeed
- Red Hat OpenShift AI 3.4
- Red Hat OpenShift AI 3.5
Timeline
- 2026-10-02 Threatist record created from CVE-2026-81726
- 2026-10-03 Alias added: GHSA-8mgp-746c-j5xp
- 2026-10-07 Affected versions changed · Red Hat
- 2026-10-20 Fix available: RHSA-2026:84734 · Red Hat
- 2026-10-20 Fix available: Red Hat OpenShift AI 3.4 · Red Hat
- 2026-10-22 Fix available: RHSA-2026:86891 · Red Hat
- 2026-10-22 Fix available: Red Hat OpenShift AI 3.5 · Red Hat
- 2026-10-30 Fix available: nltk/[email protected] · CNA
- 2026-11-02 Fix available: PyPI/[email protected] · GHSA-8mgp-746c-j5xp
References
Other 8
- https://github.com/nltk/nltk/pull/3757
- https://github.com/nltk/nltk/pull/3759
- https://github.com/nltk/nltk/pull/3813
- https://github.com/nltk/nltk/commit/2a92b71827d754ae8920261e7ed0c4bb283ab2d7
- https://github.com/nltk/nltk/commit/a44a7af69bca87e92d9c4a701fcbbe4512e8d450
- https://github.com/nltk/nltk/commit/cbc98458b43de5f792f0382583c16df39e5c5117
- https://github.com/nltk/nltk
- https://github.com/pypa/advisory-database/tree/main/vulns/nltk/PYSEC-2026-3740.yaml
More Nltk vulnerabilities
- 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
Sources
- CVE-2026-81726 · CVE Program
- CVE-2026-81726 · NVD
- FIRST EPSS
- GHSA-8mgp-746c-j5xp · GitHub Advisory Database · CC BY 4.0
- CVE-2026-81726 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences