CVE-2026-40684

A flaw was found in Exim, specifically on systems utilizing musl libc. A remote attacker can exploit this vulnerability by providing malformed DNS data within PTR records. This can lead to the mail transfer agent MTA connection instance crashing, resulting in a Denial of Service DoS for affected...

Ubuntu 22.04 LTS / 24.04 LTS / 25.10 / 26.04 LTS : Exim vulnerabilities (USN-8228-1)

The remote Ubuntu 22.04 LTS / 24.04 LTS / 25.10 / 26.04 LTS host has packages installed that are affected by multiple vulnerabilities as referenced in the USN-8228-1 advisory. It was discovered that Exim incorrectly handled parsing malformed JSON in message headers. A remote attacker could possib...

USN-8228-1: Exim vulnerabilities

It was discovered that Exim incorrectly handled parsing malformed JSON in message headers. A remote attacker could possibly use this issue to execute arbitrary code. CVE-2026-40685 It was discovered that Exim incorrectly handled processing of UTF-8 trailing characters. A remote attacker could...

USN-8228-1 exim4 vulnerabilities

It was discovered that Exim incorrectly handled parsing malformed JSON in message headers. A remote attacker could possibly use this issue to execute arbitrary code. CVE-2026-40685 It was discovered that Exim incorrectly handled processing of UTF-8 trailing characters. A remote attacker could...

CVE-2026-40686

A flaw was found in Exim when UTF-8 operators are enabled. A remote attacker could exploit this by sending malformed UTF-8 header data with large trailing characters, leading to an out-of-bounds read. This vulnerability may result in information disclosure within an error message, potentially...

CVE-2026-40686

In Exim before 4.99.2, when utf8 operators are enabled, there is an out-of-bounds read if large UTF-8 trailing characters are present malformed UTF-8 header data. Information might be divulged within an error message produced during handling of an unrelated e-mail message...

CVE-2026-40685

In Exim before 4.99.2, when JSON lookup is enabled, an out-of-bounds heap write can occur when a JSON operator encounters malformed JSON in an untrusted header, because of an incorrect implementation of \ skipping...

CVE-2026-40687

In Exim before 4.99.2, when the SPA authentication driver is used with an adversarial SPA resource, there can be an out-of-bounds write that crashes the connection instance, or erroneous data processing that divulges data from uninitialized heap memory...

CVE-2026-40684

In Exim before 4.99.2, on systems using musl libc not glibc, an attacker can crash the connection instance when malformed DNS data is present in PTR records. This is caused by a dnexpand oddity in octal printing...

EUVD-2026-26445

In Exim before 4.99.2, when the SPA authentication driver is used with an adversarial SPA resource, there can be an out-of-bounds write that crashes the connection instance, or erroneous data processing that divulges data from uninitialized heap memory...

Exim 安全漏洞

Exim is an open-source message transfer agent MTA developed by Exim Software, running on Unix systems. It primarily handles the routing, forwarding, and delivery of emails. Versions of Exim prior to 4.99.2 contained security vulnerabilities. These vulnerabilities stemmed from the SPA authenticati...

CVE-2026-40687

In Exim before 4.99.2, when the SPA authentication driver is used with an adversarial SPA resource, there can be an out-of-bounds write that crashes the connection instance, or erroneous data processing that divulges data from uninitialized heap memory...

CVE-2026-40686

In Exim before 4.99.2, when utf8 operators are enabled, there is an out-of-bounds read if large UTF-8 trailing characters are present malformed UTF-8 header data. Information might be divulged within an error message produced during handling of an unrelated e-mail message...

CVE-2026-40684

In Exim before 4.99.2, on systems using musl libc not glibc, an attacker can crash the connection instance when malformed DNS data is present in PTR records. This is caused by a dnexpand oddity in octal printing...

EUVD-2026-26442

In Exim before 4.99.2, on systems using musl libc not glibc, an attacker can crash the connection instance when malformed DNS data is present in PTR records. This is caused by a dnexpand oddity in octal printing...

CVE-2026-40686

In Exim before 4.99.2, when utf8 operators are enabled, there is an out-of-bounds read if large UTF-8 trailing characters are present malformed UTF-8 header data. Information might be divulged within an error message produced during handling of an unrelated e-mail message...

EUVD-2026-26443

In Exim before 4.99.2, when JSON lookup is enabled, an out-of-bounds heap write can occur when a JSON operator encounters malformed JSON in an untrusted header, because of an incorrect implementation of \ skipping...

CVE-2026-40686

In Exim before 4.99.2, when utf8 operators are enabled, there is an out-of-bounds read if large UTF-8 trailing characters are present malformed UTF-8 header data. Information might be divulged within an error message produced during handling of an unrelated e-mail message...

CVE-2026-40685

Exim before 4.99.2 is affected when JSON lookup is enabled. An out-of-bounds heap write can occur if a JSON operator encounters malformed JSON in an untrusted header, caused by an incorrect implementation of the JSON skipping logic. CVSS v3.1 metrics indicate a high-severity, remote-execution-lik...

CVE-2026-40686

CVE-2026-40686 affects Exim before 4.99.2 when utf8 operators are enabled. The vulnerability is an out-of-bounds read triggered by large UTF-8 trailing characters in malformed UTF-8 header data, with the potential for information disclosure via an error message produced during handling of an unre...