VDB
CVE-2026-71513
CVE-2026-71513
PUBLISHED
CVSS 8.7 HIGH
Reported by VulnCheck · Published August 22, 2026
NLTK before 3.10.3 contains a remote code execution vulnerability in AllowlistUnpickler that validates only the pickle module string and not the global name, allowing attackers to resolve dotted names by attribute traversal to callables outside the allowlisted namespace. Attackers can craft untrusted transition-parser models that execute arbitrary commands when TransitionParser.parse loads the model through allowlisted_pickle_load.
Risk Scores
CVSS 4.0
8.7
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| nltk | nltk | 3.10.0, 3.10.3 |
| PyPI | nltk | 3.10.0 |
| chainguard | nemo | 0, 0, 0 |
| wolfi | open-webui | 0, 0, 0 |
| nltk | nltk | 3.10.3, 3.10.0, 3.10.0 |
| chainguard | open-webui | 0, 0, 0 |
Timeline
- Aug 22, 2026 CVE Published
- Aug 22, 2026 Coalition ESS Score
- Aug 23, 2026 EPSS Score
- Aug 24, 2026 EPSS Score
- Aug 26, 2026 EPSS Score
- Aug 28, 2026 EPSS Score
- Aug 30, 2026 EPSS Score
- Sep 3, 2026 EPSS Score
- Sep 3, 2026 Security Advisory
- Sep 5, 2026 EPSS Score
- Sep 6, 2026 EPSS Score
- Sep 9, 2026 EPSS Score
References
- Patch Commit patch
- product
- technical-description
- VulnCheck Advisory: NLTK 3.10.0 through 3.10.2 Remote Code Execution via AllowlistUnpickler Dotted-Name Bypass third-party-advisory
- https://nvd.nist.gov/vuln/detail/CVE-2026-71513 advisory
- https://github.com/advisories/GHSA-5gh2-94qg-qppq advisory