USN-6374-1 fixed vulnerabilities in Mutt. This update provides the corresponding updates for Ubuntu 23.10.
Original advisory details:
It was discovered that Mutt incorrectly handled certain email header contents. If a user were tricked into opening a specially crafted message, a remote attacker could possibly use this issue to cause a denial of service. (CVE-2023-4874, CVE-2023-4875)