Path traversal in Natural Language Toolkit - CVE-2026-63312
Published: August 7, 2026 / Updated: September 14, 2026
Vulnerability identifier: #VU141251
CSH Severity: Medium
CVSS v4: 8.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-63312
CWE-ID: CWE-22
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to disclose sensitive information.
The vulnerability exists due to path traversal in StreamBackedCorpusView when processing a user-controlled fileid path while pathsec.ENFORCE is enabled. A remote attacker can supply a crafted file path to disclose sensitive information.
XMLCorpusView and corpus reader subclasses that pass a raw string fileid to StreamBackedCorpusView are also affected.
Affected software
Natural Language Toolkit
How to mitigate CVE-2026-63312
Install security update from vendor's website.
Natural Language Toolkit - update to 3.10.0