Ubuntu Security Notices USN-8353-1 USN-8353-1: Exim vulnerability Publication date 1 June 2026 Overview Exim could be made to expose sensitive information over the network. Releases 26.04 LTS 25.10 24.04 LTS 22.04 LTS Open side navigation Close side navigation Packages Details Update instructions References Packages exim4 - Exim is a mail transport agent Details Warisjeet Singh discovered that Exim with SUPPORT_PROXY enabled did not properly handle memory before SMTP authentication. A remote attacker could possibly use this issue to obtain sensitive information. Warisjeet Singh discovered that Exim with SUPPORT_PROXY enabled did not properly handle memory before SMTP authentication. A remote attacker could possibly use this issue to obtain sensitive information. Update instructions In general, a standard system update will make all the necessary changes. Learn more about how to get the fixes. The problem can be corrected by updating your system to the following package versions: Ubuntu Release Package Version 26.04 LTS resolute exim4 – 4.99.1-1ubuntu1.3 exim4-base – 4.99.1-1ubuntu1.3 eximon4 – 4.99.1-1ubuntu1.3 25.10 questing exim4 – 4.98.2-1ubuntu2.3 exim4-base – 4.98.2-1ubuntu2.3 eximon4 – 4.98.2-1ubuntu2.3 24.04 LTS noble exim4 – 4.97-4ubuntu4.6 exim4-base – 4.97-4ubuntu4.6 eximon4 – 4.97-4ubuntu4.6 22.04 LTS jammy exim4 – 4.95-4ubuntu2.9 exim4-base – 4.95-4ubuntu2.9 eximon4 – 4.95-4ubuntu2.9 Reduce your security exposure Ubuntu Pro provides ten-year security coverage to 25,000+ packages in Main and Universe repositories, and it is free for up to five machines. Get Ubuntu Pro References CVE-2026-48840 CVE-2026-48840