CVE-2026-12259
MEDIUM
5,3
Source: [email protected]
Attack Vector: network
Attack Complexity: high
Privileges Required: none
User Interaction: required
Scope: unchanged
Confidentiality: none
Integrity: high
Availability: none
Description
AI Translation Available
In nltk version 3.9.4, the `nltk.downloader.Downloader._download_package()` function writes downloaded package bytes to disk and may extract them before enforcing SHA-256 or MD5 checksum validation. This allows an attacker to tamper with the package response body for `info.url` through a compromised mirror, malicious proxy, or other source-substitution condition, leading to the installation of attacker-controlled package bytes. The vulnerability can result in malicious corpus or model content being trusted by downstream users or applications.
494
Download of Code Without Integrity Check
DraftCommon Consequences
Security Scopes Affected:
Integrity
Availability
Confidentiality
Other
Potential Impacts:
Execute Unauthorized Code Or Commands
Alter Execution Logic
Other
Applicable Platforms
All platforms may be affected
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