nltk is contains an Inefficient Regular Expression and is vulnerable to regular expression denial of service attacks. References https://nvd.nist.gov/vuln/detail/CVE-2021-3828 https://github.com/nltk/nltk/pull/2816 https://github.com/nltk/nltk/commit/277711ab1dec729e626b27aab6fa35ea5efbd7e6 https://huntr.dev/bounties/d19aed43-75bc-4a03-91a0-4d0bb516bc32 https://github.com/advisories/GHSA-2ww3-fxvq-293j
