CVE-2026-71513
CVE-2026-71513 · NLTK 3.10.0 through 3.10.2 Remote Code Execution via AllowlistUnpickler Dotted-Name Bypass
This page contains facts from public vulnerability sources. Check the original advisory before updating.
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.
CVSS 8.7 · High · EPSS 1.1% · Fix available
- Published
- Updated
Affected products and versions
nltk
- Versions
- ≥ 3.10.0, < 3.10.3: Affected (semver)
- 3.10.3: Not affected (semver)
Update to 3.10.3
nltk Debian:12
- Versions
- 3.10.0-1
- 3.10.1-1
- 3.10.3-1
- 3.8-1
- 3.8.1-1
- 3.9.1-1
- 3.9.1-2
- 3.9.2-1
- 3.9.3-1
- Affected ranges
- ECOSYSTEM: (−∞, +∞)
No fix published
nltk Debian:13
- Versions
- 3.10.0-1
- 3.10.1-1
- 3.10.3-1
- 3.9.1-2
- 3.9.2-1
- 3.9.3-1
- Affected ranges
- ECOSYSTEM: (−∞, +∞)
No fix published
nltk Debian:14
- Versions
- 3.10.0-1
- 3.10.1-1
- 3.9.1-2
- 3.9.2-1
- 3.9.3-1
- Affected ranges
- ECOSYSTEM: < 3.10.3-1
Update to 3.10.3-1
nltk PyPI
- Versions
- 3.10.0
- 3.10.1
- 3.10.2
- Affected ranges
- ECOSYSTEM: ≥ 3.10.0, < 3.10.3
Update to 3.10.3
nltk Ubuntu:Pro:14.04:LTS
- Versions
- 2.0~b9-0ubuntu4
- 2.0~b9-0ubuntu4.1~esm2
- 2.0~b9-0ubuntu4.1~esm4
- 2.0~b9-0ubuntu4.1~esm5
- 2.0~b9-0ubuntu4.1~esm6
- Affected ranges
- ECOSYSTEM: (−∞, +∞)
No fix published
nltk Ubuntu:Pro:16.04:LTS
- Versions
- 3.0.4-1
- 3.0.5-1
- 3.1-1
- 3.1-1ubuntu0.1
- 3.1-1ubuntu0.1+esm1
- 3.1-1ubuntu0.1+esm2
- 3.1-1ubuntu0.1+esm3
- 3.1-1ubuntu0.1+esm4
- Affected ranges
- ECOSYSTEM: (−∞, +∞)
No fix published
nltk Ubuntu:Pro:18.04:LTS
- Versions
- 3.2.4-1
- 3.2.5-1
- 3.2.5-1ubuntu0.1
- 3.2.5-1ubuntu0.1+esm1
- 3.2.5-1ubuntu0.1+esm2
- 3.2.5-1ubuntu0.1+esm3
- 3.2.5-1ubuntu0.1+esm4
- Affected ranges
- ECOSYSTEM: (−∞, +∞)
No fix published
nltk Ubuntu:Pro:20.04:LTS
- Versions
- 3.4.5-1
- 3.4.5-2
- 3.4.5-2ubuntu0.1~esm1
- 3.4.5-2ubuntu0.1~esm2
- 3.4.5-2ubuntu0.1~esm3
- 3.4.5-2ubuntu0.1~esm4
- Affected ranges
- ECOSYSTEM: (−∞, +∞)
No fix published
nltk Ubuntu:Pro:22.04:LTS
- Versions
- 3.5-1
- 3.6.5-1
- 3.6.7-1
- 3.7-1
- 3.7-1ubuntu0.1~esm1
- 3.7-1ubuntu0.1~esm2
- Affected ranges
- ECOSYSTEM: (−∞, +∞)
No fix published
nltk Ubuntu:Pro:24.04:LTS
- Versions
- 3.8.1-1
- 3.8.1-1ubuntu0.1~esm1
- 3.8.1-1ubuntu0.1~esm2
- Affected ranges
- ECOSYSTEM: (−∞, +∞)
No fix published
nltk Ubuntu:26.10
- Versions
- 3.9.2-1
- 3.9.3-1
- 3.10.0-1
- 3.10.1-1
- 3.10.3-1
- Affected ranges
- ECOSYSTEM: (−∞, +∞)
No fix published
nltk Ubuntu:Pro:26.04:LTS
- Versions
- 3.9.1-2
- 3.9.1-2build1
- 3.9.2-1
- 3.9.2-1ubuntu0.1~esm1
- 3.9.2-1ubuntu0.1~esm2
- Affected ranges
- ECOSYSTEM: (−∞, +∞)
No fix published
Original sources
- https://github.com/nltk/nltk/commit/c3e37113742a1ebeeb4f2ca58941f320f98805ea
- https://github.com/nltk/nltk
- https://github.com/nltk/nltk/blob/v3.10.2/nltk/picklesec.py#L119-L124
- https://www.vulncheck.com/advisories/nltk-through-remote-code-execution-via-allowlistunpickler-dotted-name-bypass
- https://nvd.nist.gov/vuln/detail/CVE-2026-71513