CVE-2026-62388
Description
A flaw was found in NLTK. The software's default settings in pathsec.py cause security checks to only issue warnings rather than actively preventing malicious actions. This allows attackers to bypass safeguards designed to prevent unauthorized access to files (path traversal) and the execution of harmful code through data processing (pickle deserialization). Consequently, attackers can exploit these disabled security controls to compromise the system.
Statement
NLTK versions before 3.10.0 in Red Hat products are configured by default to not enforce security validations for path traversal and pickle deserialization. This insecure default allows attackers to bypass these protections, as security controls are only active when manually enabled, increasing the risk of arbitrary code execution or unauthorized file access.
Mitigation
To mitigate this issue, ensure that the NLTK security validation enforcement is enabled. This can be achieved by setting `nltk.internals.pathsec.ENFORCE = True` in your application's initialization code before processing untrusted data. This change may require restarting any services or applications that utilize NLTK.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
The following CVSS metrics and score provided are preliminary and subject to review.
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 7.5 | N/A | 7.5 |
| Attack Vector | Network | N/A | Network |
| Attack Complexity | Low | N/A | Low |
| Privileges Required | None | N/A | None |
| User Interaction | None | N/A | None |
| Scope | Unchanged | N/A | Unchanged |
| Confidentiality | High | N/A | High |
| Integrity Impact | None | N/A | None |
| Availability Impact | None | N/A | None |
Vector
Red Hat: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
cve.org: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
Understanding the Weakness (CWE)
Other
Technical Impact: Varies by Context
The impact of insecure defaults varies widely depending on the functionality that the product controls.
Frequently Asked Questions
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