Vulnerability DatabaseCVE-2026-63310
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CVE-2026-63310
Published:August 22, 2026
Updated:August 25, 2026
NLTK before 3.9.3 fails to verify file integrity after downloading packages and before extraction in the downloader module. Attackers can perform man-in-the-middle attacks or DNS poisoning to inject malicious package contents that are extracted without validation.
Affected Packages
nltk (CONDA):
Affected version(s) >=2.0.3 <3.9.3
Fix Suggestion:
Update to version 3.9.3
nltk (PYTHON):
Affected version(s) >=0.8 <3.9.3
Fix Suggestion:
Update to version 3.9.3
Related Resources (4)
https://www.vulncheck.com/advisories/nltk-before-missing-post-download-integrity-verification
https://github.com/nltk/nltk/security/advisories/GHSA-5wp5-5229-5g6q
https://nvd.nist.gov/vuln/detail/CVE-2026-63310
https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/63xxx/CVE-2026-63310.json
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CVSS v4
Base Score:
9.3
Attack Vector
NETWORK
Attack Complexity
LOW
Attack Requirements
NONE
Privileges Required
NONE
User Interaction
NONE
Vulnerable System Confidentiality
HIGH
Vulnerable System Integrity
HIGH
Vulnerable System Availability
HIGH
Subsequent System Confidentiality
NONE
Subsequent System Integrity
NONE
Subsequent System Availability
NONE
CVSS v3
Base Score:
7.1
Attack Vector
NETWORK
Attack Complexity
HIGH
Privileges Required
NONE
User Interaction
REQUIRED
Scope
UNCHANGED
Confidentiality
LOW
Integrity
HIGH
Availability
HIGH
Weakness Type (CWE)
Download of Code Without Integrity Check
CWE-494
EPSS
Base Score:
0.11