Deserialization of Untrusted Data in Natural Language Toolkit - CVE-2026-78683
Published: August 11, 2026 / Updated: September 14, 2026
Vulnerability identifier: #VU141419
CSH Severity: High
CVSS v4: 8.6 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-78683
CWE-ID: CWE-502
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to execute arbitrary code.
The vulnerability exists due to deserialization of untrusted data in TransitionParser.parse() when loading a user-supplied model file. A remote attacker can supply a specially crafted pickle file to execute arbitrary code.
User interaction is required to load the crafted model file.
Affected software
Natural Language Toolkit
How to mitigate CVE-2026-78683
Install security update from vendor's website.
Natural Language Toolkit - update to 3.10.0