The nltk package is vulnerable to ReDoS (regular expression denial of service). An attacker that is able to provide as an input to the [_read_comparison_block()(https://github.com/nltk/nltk/blob/23f4b1c4b4006b0cb3ec278e801029557cec4e82/nltk/corpus/reader/comparative_sents.py#L259) function in the file nltk/corpus/reader/comparative_sents.py may cause an application to consume an excessive amount of CPU.
{
"cwe_ids": [
"CWE-1333",
"CWE-697"
],
"nvd_published_at": "2021-09-27T13:15:00Z",
"github_reviewed_at": "2021-09-28T20:49:37Z",
"github_reviewed": true,
"severity": "HIGH"
}