CVE-2026-78680

Description

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 Vector

References

• https://github.com/nltk/nltk/security/advisories/GHSA-6hwm-xvph-95vm
• https://www.vulncheck.com/advisories/nltk-before-arbitrary-code-execution-via-graphviz-dot-binary
• https://github.com/nltk/nltk/security/advisories/GHSA-6hwm-xvph-95vm