CVE-2017-17846
An issue was discovered in Enigmail before 1.9.9. Regular expressions are exploitable for Denial of Service, because of attempts to match arbitrarily long strings, aka TBE-01-003.
Date published : 2017-12-22
https://www.debian.org/security/2017/dsa-4070
https://enigmail.net/download/other/Enigmail%20Pentest%20Report%20by%20Cure53%20-%20Excerpt.pdf