CVE Explorer
CVE-2026-12243
NLTK version 3.9.4 is vulnerable to a path traversal attack due to an incomplete fix for GitHub Issue #3504. The `_UNSAFE_NO_PROTOCOL_RE` regex in `nltk/data.py` checks for literal `../` sequences but fails to account for percent-encoded traversal sequences such as `..%2f`. The `url2pathname()` function decodes these sequences after the validation step, allowing an attacker to bypass the protection. This vulnerability enables an attacker to read arbitrary files accessible to the Python process b
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:v2:03c950712dc55b0d9d12d7c514e7c2e589b698f0ebf4ffa768f0d129b25c88c9 · sha256:508e7d7dcac3c4b9… · /containers/cna/affected/0
Provider-owned CVSS observations
1 source assertion{"metric":{"attackComplexity":"LOW","attackVector":"NETWORK","availabilityImpact":"NONE","baseScore":7.5,"baseSeverity":"HIGH","confidentialityImpact":"HIGH","integrityImpact":"NONE","privilegesRequired":"NONE","scope":"UNCHANGED","userInteraction":"NONE","vectorString":"CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N","version":"3.0"},"metric_type":"cvssV3_0"}
- cve_program_cvelist_v5cvssurn:baitaphish:normalized-source-record:v2:03c950712dc55b0d9d12d7c514e7c2e589b698f0ebf4ffa768f0d129b25c88c9 · sha256:508e7d7dcac3c4b9… · /containers/cna/metrics/0/cvssV3_0
CWE assertions
1 source assertion{"cweId":"CWE-22","description":"CWE-22 Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')","lang":"en","type":"CWE"}
- cve_program_cvelist_v5cweurn:baitaphish:normalized-source-record:v2:03c950712dc55b0d9d12d7c514e7c2e589b698f0ebf4ffa768f0d129b25c88c9 · sha256:508e7d7dcac3c4b9… · /containers/cna/problemTypes/0/descriptions/0
Source references
2 source assertions{"url":"https://huntr.com/bounties/39aa9354-54ca-4e77-96da-580eb1fe6ed1"}
- cve_program_cvelist_v5referenceurn:baitaphish:normalized-source-record:v2:03c950712dc55b0d9d12d7c514e7c2e589b698f0ebf4ffa768f0d129b25c88c9 · sha256:508e7d7dcac3c4b9… · /containers/cna/references/0
{"tags":["exploit"],"url":"https://huntr.com/bounties/39aa9354-54ca-4e77-96da-580eb1fe6ed1"}
- cve_program_cvelist_v5referenceurn:baitaphish:normalized-source-record:v2:03c950712dc55b0d9d12d7c514e7c2e589b698f0ebf4ffa768f0d129b25c88c9 · sha256:508e7d7dcac3c4b9… · /containers/adp/0/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.