USN-8382-1: Exim vulnerabilities

Timo Longin discovered that Exim incorrectly handled certain SMTP messages
in PIPELINING/CHUNKING configurations. A remote attacker could possibly use
this issue to perform SMTP smuggling. This issue only affected Ubuntu
14.04 LTS. (CVE-2023-51766)

It was discovered that Exim incorrectly handled certain malformed JSON
data in headers. A remote attacker could possibly use this issue to crash
Exim, resulting in a denial of service, or execute arbitrary code. This
issue only affected Ubuntu 20.04 LTS. (CVE-2026-40685)

It was discovered that Exim incorrectly handled certain malformed UTF-8
headers. A remote attacker could possibly use this issue to obtain
sensitive information. This issue only affected Ubuntu 20.04 LTS.
(CVE-2026-40686)

It was discovered that Exim incorrectly handled certain SPA resources.
A remote attacker could possibly use this issue to crash Exim, resulting in
a denial of service, or obtain sensitive information. This issue only
affected Ubuntu 20.04 LTS. (CVE-2026-40687)

It was discovered that Exim incorrectly handled certain CHUNKING
transfers in some GnuTLS configurations. A remote attacker could possibly
use this issue to crash Exim, resulting in a denial of service, or execute
arbitrary code. This issue only affected Ubuntu 20.04 LTS. (CVE-2026-45185)

Warisjeet Singh discovered that Exim incorrectly handled certain proxy
connections in builds with proxy support enabled. A remote attacker could
possibly use this issue to obtain sensitive information. This issue only
affected Ubuntu 16.04 LTS, Ubuntu 18.04 LTS, and Ubuntu 20.04 LTS.
(CVE-2026-48840)