High severity · published Aug 22, 2026
CVE-2026-62388
NLTK before 3.10.0 Insecure Default Configuration in pathsec.py
7.5
CVSS
0.5%
EPSS
No
On KEV
Description
NLTK versions before 3.10.0 default to ENFORCE=False in pathsec.py, causing all security validation functions to emit warnings instead of raising exceptions. Attackers can bypass path traversal and pickle deserialization protections by exploiting the disabled security controls that are only active when manually enabled.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
High
Integrity
None
Availability
None
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.5% · higher than 43% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
NL
nltk · nltk
before 3.10.0 · source: vendor, NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-62388
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-62388
Exploit
https://github.com/nltk/nltk/security/advisories/GHSA-p3m8-78j2-g5p3
Third Party Advisory
https://www.vulncheck.com/advisories/nltk-before-insecure-default-configuration-pathsec
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