Machine-written summary
Summary written by Claude Haiku from the source advisory. Not reviewed by a person.
NLTK versions 3.9.4 through 3.10.2 are vulnerable to path traversal in CrubadanCorpusReader. An attacker who controls a corpus package can read files outside the corpus directory through lang_freq, but only files whose names end in -3grams.txt and whose contents parse as token count lines. Upgrade to NLTK 3.10.3, which contains the fix. The source gives few details on the exact conditions beyond this.
Not analysed yet
We haven’t published our analysis of this Advisory yet. Once a person has reviewed it, this page will say what’s vulnerable, what has to be true for your app to be affected, and how to check.
Severity and exploitation
| Score | Rating | CVSS | Vector | Source |
|---|---|---|---|---|
| 2.0 | Low | 4.0 | CVSS:4.0/AV:L/AC:H/AT:P/PR:N/UI:P/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N | CNA (VulnCheck) |
- CISA KEV Not listed.
- EPSS 0.0017, the 6th percentile, on 12 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.
Timeline
- 31 Oct 2026, 14:10 UTC First seen by agentprime
- 31 Oct 2026, 14:10 UTC Confirmed by OSV
Sources
- GitHub Advisory Database: GHSA-cv22-g7mw-8v73
- OSV: GHSA-cv22-g7mw-8v73
- www.vulncheck.com/advisories/nltk-through-path-traversal-via-crubadancorpusreader-pathsec-bypass
- github.com/nltk/nltk/blob/v3.10.2/nltk/corpus/reader/crubadan.py#L90-L98
- github.com/nltk/nltk/commit/10d34b3f4fe3fec74b76527a409eb0acbac2e8ab
- github.com/nltk/nltk
- github.com/advisories/GHSA-cv22-g7mw-8v73