Actively exploited in the wild
Exim Out-of-bounds Write Vulnerability
Exim - Exim Internet Mailer · Listed in the CISA KEV since 2022-03-03. This indicates confirmed attacks in production environments.
Required action: Apply updates per vendor instructions.
CVE-2019-16928
CriticalCVSS 9.8KEVSummary
Exim 4.92 through 4.92.2 allows remote code execution, a different vulnerability than CVE-2019-15846. There is a heap-based buffer overflow in string_vformat in string.c involving a long EHLO command.
Risk Assessment
An attacker can remotely execute arbitrary code on the mail server, leading to full system compromise. This could result in data theft, spam distribution, or using the server for further attacks.
Recommendation
Immediately update Exim to version 4.92.3 or later. Until patched, restrict SMTP access from untrusted sources.
Other vulnerabilities in Exim
See all- CVE-2016-1531High
Exim versions before 4.86.2, when installed setuid root, allow local users to gain privileges via the perl_startup argument.
- CVE-2026-45185Critical
Exim versions before 4.99.3, in certain GnuTLS configurations, has a use-after-free vulnerability in the BDAT body parsing path. This can lead to heap corruption when a client sends a TLS close_notify mid-body during a CHUNKING transfer, followed by a final cleartext byte on the same TCP connection.
- CVE-2019-10149CriticalActively exploited
A flaw was found in Exim versions 4.87 to 4.91 (inclusive). Improper validation of recipient address in deliver_message() function in /src/deliver.c may lead to remote command execution.
- CVE-2018-6789CriticalActively exploited
An issue was discovered in the base64d function in the SMTP listener in Exim before 4.90.1. Sending a handcrafted message may cause a buffer overflow, which can be used to execute code remotely.
- CVE-2026-66141High
In Exim before 4.99.5, a privilege escalation vulnerability exists via .forward files. The force_command for pipe transport is mishandled, allowing arbitrary command execution with elevated privileges.
- CVE-2026-66140High
In Exim before version 4.99.5, mishandling of arguments related to queue-name allows directory traversal outside the spool area, potentially leading to privilege escalation.
- CVE-2026-48840Medium
Exim 4.88 before 4.99.4 in some proxy configurations mishandles short payloads, disclosing uninitialized stack memory values to a client.
- CVE-1999-0971High
Buffer overflow in Exim allows local users to gain root privileges via a long :include: option in a .forward file.
Original NVD description (English source)
Exim 4.92 through 4.92.2 allows remote code execution, a different vulnerability than CVE-2019-15846. There is a heap-based buffer overflow in string_vformat in string.c involving a long EHLO command.