CVE-2026-62388
NLTK before 3.10.0 Insecure Default Configuration in pathsec.py
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.
INFO
Published Date :
Aug. 22, 2026, 3:16 p.m.
Last Modified :
Oct. 14, 2026, 1:10 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | |||||
| CVSS 3.1 | HIGH | 83251b91-4cc7-4094-a5c7-464a1b83ea10 | ||||
| CVSS 3.1 | HIGH | [email protected] | ||||
| CVSS 3.1 | HIGH | MITRE-CVE | ||||
| CVSS 4.0 | HIGH | 83251b91-4cc7-4094-a5c7-464a1b83ea10 | ||||
| CVSS 4.0 | HIGH | [email protected] |
Solution
- Update NLTK to version 3.10.0 or later.
- Manually enable security controls if updating is not possible.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-62388.
| URL | Resource |
|---|---|
| https://github.com/nltk/nltk/security/advisories/GHSA-p3m8-78j2-g5p3 | Exploit Mitigation Vendor Advisory |
| https://www.vulncheck.com/advisories/nltk-before-insecure-default-configuration-pathsec | Third Party Advisory |
| https://github.com/nltk/nltk/security/advisories/GHSA-p3m8-78j2-g5p3 | Exploit Mitigation Vendor Advisory |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-62388 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-62388
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-62388 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-62388 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
CVE Translated by [email protected]
Oct. 14, 2026
Action Type Old Value New Value Added Translation Title: nltk, Description: Las versiones de NLTK anteriores a la 3.10.0 tienen ENFORCE=False por defecto en pathsec.py, lo que provoca que todas las funciones de validación de seguridad emitan advertencias en lugar de lanzar excepciones. Los atacantes pueden eludir las protecciones de salto de ruta y deserialización de pickle al explotar los controles de seguridad deshabilitados que solo están activos cuando se habilitan manualmente. -
Initial Analysis by [email protected]
Aug. 27, 2026
Action Type Old Value New Value Added CPE Configuration OR *cpe:2.3:a:nltk:nltk:*:*:*:*:*:*:*:* versions up to (excluding) 3.10.0 Added Reference Type VulnCheck: https://github.com/nltk/nltk/security/advisories/GHSA-p3m8-78j2-g5p3 Types: Exploit, Mitigation, Vendor Advisory Added Reference Type CISA-ADP: https://github.com/nltk/nltk/security/advisories/GHSA-p3m8-78j2-g5p3 Types: Exploit, Mitigation, Vendor Advisory Added Reference Type VulnCheck: https://www.vulncheck.com/advisories/nltk-before-insecure-default-configuration-pathsec Types: Third Party Advisory -
CVE Modified by [email protected]
Aug. 26, 2026
Action Type Old Value New Value Added Reference https://github.com/nltk/nltk/security/advisories/GHSA-p3m8-78j2-g5p3 Added Reference https://www.vulncheck.com/advisories/nltk-before-insecure-default-configuration-pathsec Removed Reference https://github.com/nltk/nltk/security/advisories/GHSA-p3m8-78j2-g5p3 Removed Reference https://www.vulncheck.com/advisories/nltk-before-insecure-default-configuration-pathsec -
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Aug. 26, 2026
Action Type Old Value New Value Added Reference https://github.com/nltk/nltk/security/advisories/GHSA-p3m8-78j2-g5p3 Added SSVC {'id': 'CVE-2026-62388', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'poc'}, {'automatable': 'yes'}, {'technicalImpact': 'partial'}], 'version': '2.0.3', 'timestamp': '2026-08-26T17:53:47.950536Z'} -
New CVE Received by [email protected]
Aug. 22, 2026
Action Type Old Value New Value Added Affected [{'vendor': 'nltk', 'product': 'nltk', 'versions': [{'status': 'affected', 'version': '0', 'lessThan': '3.10.0', 'versionType': 'semver'}, {'status': 'unaffected', 'version': '3.10.0', 'versionType': 'semver'}], 'packageURL': 'pkg:pypi/nltk', 'defaultStatus': 'unaffected'}] Added 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. Added CVSS V4.0 AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N Added CWE CWE-1188 Added Reference https://github.com/nltk/nltk/security/advisories/GHSA-p3m8-78j2-g5p3 Added Reference https://www.vulncheck.com/advisories/nltk-before-insecure-default-configuration-pathsec