CVE Explorer
CVE-2026-12259
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 be
Known exploited
Not asserted
Disputed
No
Stale source
No
Conflicts
0
Affected products and versions
1 source assertion{"product":"nltk/nltk","vendor":"nltk","versions":[{"lessThanOrEqual":"latest","status":"affected","version":"unspecified","versionType":"custom"}]}
- cve_program_cvelist_v5affectedurn:baitaphish:normalized-source-record:v2:b213c79742d86d56e2b814421b1d284e73f8bd5919742440aa0df70f71620d84 · sha256:ea9243c22ce9220f… · /containers/cna/affected/0
Provider-owned CVSS observations
1 source assertion{"metric":{"attackComplexity":"HIGH","attackVector":"NETWORK","availabilityImpact":"NONE","baseScore":5.3,"baseSeverity":"MEDIUM","confidentialityImpact":"NONE","integrityImpact":"HIGH","privilegesRequired":"NONE","scope":"UNCHANGED","userInteraction":"REQUIRED","vectorString":"CVSS:3.0/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:H/A:N","version":"3.0"},"metric_type":"cvssV3_0"}
- cve_program_cvelist_v5cvssurn:baitaphish:normalized-source-record:v2:b213c79742d86d56e2b814421b1d284e73f8bd5919742440aa0df70f71620d84 · sha256:ea9243c22ce9220f… · /containers/cna/metrics/0/cvssV3_0
CWE assertions
1 source assertion{"cweId":"CWE-494","description":"CWE-494 Download of Code Without Integrity Check","lang":"en","type":"CWE"}
- cve_program_cvelist_v5cweurn:baitaphish:normalized-source-record:v2:b213c79742d86d56e2b814421b1d284e73f8bd5919742440aa0df70f71620d84 · sha256:ea9243c22ce9220f… · /containers/cna/problemTypes/0/descriptions/0
Source references
1 source assertion{"url":"https://huntr.com/bounties/659ccf6d-12d4-4d4a-84c0-078633c35a5d"}
- cve_program_cvelist_v5referenceurn:baitaphish:normalized-source-record:v2:b213c79742d86d56e2b814421b1d284e73f8bd5919742440aa0df70f71620d84 · sha256:ea9243c22ce9220f… · /containers/cna/references/0
Attribution and limitations
- CVE Program CVEList V5: Reproduce the MITRE copyright designation and CVE license in copies. Source →
Provider severity values are preserved separately. Baitaphish does not convert them into a risk rating, infer affected products, or treat EPSS as observed exploitation.