calibre before 5.32.0 contains a regular expression that is vulnerable to ReDoS (Regular Expression Denial of Service) in htmlpreprocessrules in ebooks/conversion/preprocess.py.
{ "versions": [ { "introduced": "0" }, { "fixed": "5.32.0" } ] }
"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2021-44686.json"
[ { "events": [ { "introduced": "0" }, { "last_affected": "34" } ] } ]