What is CVE-2026-81726?

CVE-2026-81726 is a high-severity vulnerability in Nltk, classified under External Control of File Name or Path. CVSS score: 7.0/10. Published 2026-08-27.

How severe is CVE-2026-81726?

High severity. CVSS v3 base score is 7.0 out of 10.

Vulnerability in Nltk

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.

CVSS v3 metric

CVSS v3 base score 7.0 (High). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:L/A:L.

Affected products

Nltk

Weakness classification (CWE)

CWE-73 — External Control of File Name or Path

References

disclosure@vulncheck.com (vendor-advisory)
disclosure@vulncheck.com (third-party-advisory)

Frequently asked questions

What is CVE-2026-81726?: CVE-2026-81726 is a high-severity vulnerability in Nltk, classified under External Control of File Name or Path. CVSS score: 7.0/10. Published 2026-08-27.
How severe is CVE-2026-81726?: High severity. CVSS v3 base score is 7.0 out of 10.