Vulnerability in Nltk

CVE-2026-78680

NLTK versions before 3.10.3 fail to use validated absolute paths when invoking the Graphviz dot binary in dependencygraph.dot2img and AlignedSent._repr_svg_, allowing attackers to execute arbitrary code by placing a malicious dot binary in the search path or current working directory. Attackers can exploit bare-name binary resolution on Windows via the current working directory or on Unix-like systems via relative PATH entries to execute their binary instead of the legitimate Graphviz tool.

CVSS v3 metric

CVSS v3 base score 7.8 (High). Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-78680?
CVE-2026-78680 is a high-severity vulnerability in Nltk, classified under Untrusted Search Path. CVSS score: 7.8/10. Published 2026-08-25.
How severe is CVE-2026-78680?
High severity. CVSS v3 base score is 7.8 out of 10.