Download of Code Without Integrity Check Affecting nltk package, versions *
Threat Intelligence
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
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Test your applications- Snyk IDSNYK-ECHOLATEST-NLTK-18516564
- published4 Aug 2026
- disclosed3 Aug 2026
Introduced: 3 Aug 2026
NewCVE-2026-12259 (opens in a new tab)How to fix?
There is no fixed version for Echo:latest nltk.
NVD Description
Note: Versions mentioned in the description apply only to the upstream nltk package and not the nltk package as distributed by Echo.
See How to fix? for Echo:latest relevant fixed versions and status.
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.