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CVE-2021-3842Inefficient Regular Expression Complexity in nltk/nltk
- 7.5HighCVSS base score
- 1.6%Exploitation in 30 daysEPSS · top 24% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- NonePublic exploitsnone known yet
Description
nltk is vulnerable to Inefficient Regular Expression Complexity
Timeline
ID reserved
By @huntrdev
- 3 months later
· 3 months later
Published
- 3 years later
· 3 years later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| @huntrdevCNA (assigner) | 3.0 | High7.5 | CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
| NVDNVD · Modified | 3.1 | High7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
- EPSS (exploitation in 30 days)
- 1.6% · top 24% of all CVEs (13 Nov 2026)
Loading the EPSS history…
The list uses the assigner's score when there is one, then CISA's, then NVD's: High 7.5.
Affected products
Affected packages
From reviewed advisories of the GitHub Advisory Database.
References
References2
- https://huntr.dev/bounties/761a761e-2be2-430a-8d92-6f74ffe9866a (opens in a new tab)x_refsource_CONFIRMx_transferred
- https://github.com/nltk/nltk/commit/2a50a3edc9d35f57ae42a921c621edc160877f4d (opens in a new tab)x_refsource_MISCx_transferred
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2022-0162 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisory GHSA-rqjh-jp2r-59cj (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2021-3842)Record last updated .