NLTK through 3.10.3 Path Traversal via Model-Artifact APIs
NLTK through 3.10.3 is exposed when pathsec is enabled and the application lets untrusted workflows choose model import or export paths. No vendor rating or fix is listed.
- Published
- Last modified
- Where the record stands: published, rejected by its publisher, or superseded by another id.What do these mean? →
- published
- Whether CISA lists it in its Known Exploited Vulnerabilities catalog: proof that attackers are using it.What do these mean? →
- Not listed in CISA KEV
- How many real-world setups can hit the bug, from the vendor's advisory and CISA data. It does not know your setup.What do these mean? →
- Specific setups only
- Fix
- Fixed in 3.10.3
- Whether working attack code is public (Exploit-DB, Metasploit, Nuclei or GitHub). Public code makes attacks easier.What do these mean? →
- None on Exploit-DB, Metasploit or GitHub
- Exploitation: poc
- Automatable: no
- Technical impact: partial
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.
Timeline
- CVE published
- CISA SSVC assessment
Exploitation: poc · Automatable: no · Technical impact: partial
- Record last updated
Affected versions
- nltk nltk
through 3.10.3
- nltkPyPI
through 3.10.3
- nltkPyPI
fixed in 3.10.3
References 2
GitHub · nltk/nltk
Questions about CVE-2026-81726
What does this mean?
Pathsec, NLTK's containment for local files, can be bypassed through model saving and loading APIs. This can let an attacker read or overwrite files outside the approved sandbox roots.Source: vulncheck.com, github.com
Am I affected, and how do I check?
Versions through 3.10.3 are listed as affected. The exposed setup requires pathsec to be enabled and untrusted workflows to be able to choose model import or export paths; check your NLTK version and whether pathsec is enabled in your application's configuration.Source: vulncheck.com, github.com
What should I do about it?
The facts do not confirm a fixed release. One version range lists 3.10.3 as fixed, while the others list it as the last affected version, so confirm the fixed version with the NLTK project before relying on an upgrade.Source: vulncheck.com, github.com
Is it being exploited?
It is not in CISA's Known Exploited Vulnerabilities catalog, and CISA's SSVC assessment does not mark exploitation as active. That does not mean it has not been attacked: vendors and researchers can report attacks before CISA lists them. CISA's SSVC assessment notes a proof of concept exists. No public exploit code is tracked.Source: cve.now feed data