High severity · published Aug 27, 2026
CVE-2026-81726
NLTK through 3.10.3 Path Traversal via Model-Artifact APIs
7.0
CVSS
0.3%
EPSS
No
On KEV
Description
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.
CVSS vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:L/A:L
Attack vector
Network
Complexity
High
Privileges
None
User interaction
None
Confidentiality
High
Integrity
Low
Availability
Low
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.3% · higher than 27% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
NL
nltk · nltk
through 3.10.3 · source: vendor, NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-81726
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-81726
Exploit
https://github.com/nltk/nltk/security/advisories/GHSA-8mgp-746c-j5xp
Third Party Advisory
https://www.vulncheck.com/advisories/nltk-through-3.10.3-path-traversal-via-model-artifact-apis
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