Bug#1148506: exim4: CVE-2026-94054 CVE-2026-94055 CVE-2026-94056 CVE-2026-94057

[Salvatore Bonaccorso]

Source: exim4
Version: 4.100-3
Severity: grave
Tags: security upstream
Justification: user security hole
X-Debbugs-Cc: carnil at debian.org, Debian Security Team <team at security.debian.org>

Hi,

The following vulnerabilities were published for exim4.

Andreas, I'm putting this at RC level, but I'm not sure how common
exploitable setups are for the more severe ones.

CVE-2026-94054[0]:
| Exim before 4.100.1, when Proxy-Protocol is used with an attacker-
| controlled proxy, has an out-of-bounds write.


CVE-2026-94055[1]:
| Exim before 4.100.1, when certain non-default TLS settings are used
| with GnuTLS, has a use-after-free.


CVE-2026-94056[2]:
| Exim before 4.100.1, when Proxy-Protocol is used with an attacker-
| controlled proxy, allows attackers to read certain uninitialized
| data from stack memory.


CVE-2026-94057[3]:
| 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.


If you fix the vulnerabilities please also make sure to include the
CVE (Common Vulnerabilities & Exposures) ids in your changelog entry.

For further information see:

[0] https://security-tracker.debian.org/tracker/CVE-2026-94054
    https://www.cve.org/CVERecord?id=CVE-2026-94054
[1] https://security-tracker.debian.org/tracker/CVE-2026-94055
    https://www.cve.org/CVERecord?id=CVE-2026-94055
[2] https://security-tracker.debian.org/tracker/CVE-2026-94056
    https://www.cve.org/CVERecord?id=CVE-2026-94056
[3] https://security-tracker.debian.org/tracker/CVE-2026-94057
    https://www.cve.org/CVERecord?id=CVE-2026-94057
[4] https://lists.exim.org/lurker/message/20260918.121220.0f87338e.en.html

Please adjust the affected versions in the BTS as needed.

Regards,
Salvatore