CVE-2019-10741: K-9 Mail Project K-9 Mail

Medium severity, CVSS 4.3. EPSS: 0.9% chance of exploitation in the next 30 days.

K-9 Mail v5.600 can include the original quoted HTML code of a specially crafted, benign looking, email within (digitally signed) reply messages. The quoted part can contain conditional statements that show completely different text if opened in a different email client. This can be abused by an attacker to obtain valid S/MIME or PGP signatures for arbitrary content to be displayed to a third party. NOTE: the vendor states "We don't plan to take any action because of this."

Affected products

• K-9 Mail Project K-9 Mail: version 5.600 only

Published 2019-04-07. Last modified 2026-06-17.