CVE-2026-81726

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.

  • Published Aug 27, 2026
  • CVSS 8.3 high
  • 0.3% chance of exploitation in the next 30 days (EPSS)
  • Public exploit code is available

Affected software

CVE-2026-81726 at the National Vulnerability Database