CVE-2026-94057

Exim before 4.100.1 allows SMTP smuggling in which the received message does not match any sent message, and instead depends on crafted data sent after a rejection during DATA processing.

Exim before 4.100.1 allows SMTP smuggling in which the received message does not match any sent message, and instead depends on crafted data sent after a rejection during DATA processing.

Exim before 4.100.1 allows SMTP smuggling in which the received message does not match any sent message, and instead depends on crafted data sent after a rejection during DATA processing.

Exim before 4.100.1 allows SMTP smuggling in which the received message does not match any sent message, and instead depends on crafted data sent after a rejection during DATA processing.

Exim before 4.100.1 allows SMTP smuggling in which the received message does not match any sent message, and instead depends on crafted data sent after a rejection during DATA processing.

Exim before 4.100.1 allows SMTP smuggling in which the received message does not match any sent message, and instead depends on crafted data sent after a rejection during DATA processing.

• CVE-2026-94054: fix out-of-bounds read in Proxy Protocol v1 header parsing
• CVE-2026-94057: avoid more SMTP smuggling attack types by honouring strict CRLF mode when swallowing input after a data-phase rejection

• CVE-2026-94054: recompute the PROXY protocol v1 header length from the copied line in proxy_protocol_host(), so the following memchr() and end-of-line store cannot read or write past the allocation
• CVE-2026-94057: make read_message_data_smtp() honour the strict-CRLF state of the current message when receive_swallow_smtp() drains input after a DATA rejection, preventing further SMTP smuggling variants

It was discovered that Exim had an out-of-bounds write when Proxy-Protocol was used with an attacker-controlled proxy. A remote attacker could possibly use this issue to execute arbitrary code. (CVE-2026-94054)

It was discovered that Exim had a use-after-free when certain non-default TLS settings were used with GnuTLS. A remote attacker could possibly use this issue to cause Exim to crash, resulting in a denial of service. This issue only affected Ubuntu 26.04 LTS. (CVE-2026-94055)

It was discovered that Exim allowed attackers to read uninitialized data from stack memory when Proxy-Protocol was used with an attacker-controlled proxy. A remote attacker could possibly use this issue to obtain sensitive information. (CVE-2026-94056)

It was discovered that Exim allowed SMTP smuggling via crafted data sent after a rejection during DATA processing. A remote attacker could possibly use this issue to inject arbitrary email messages. (CVE-2026-94057)