CVE-2026-24031

CVE-2026-24031 describes a vulnerability in Dovecot where SQL-based authentication can be bypassed if an admin clears the auth_username_chars setting. This allows bypassing authentication for any user and enables user enumeration. The root cause is tied to the handling of auth_username_chars; whe...

CVE-2026-27857

The CVE-2026-27857 issue affects the Dovecot IMAP server where sending a NOOP with 4000+ parentheses causes about 1 MB of memory to be allocated for each connection. Attackers could spawn many connections (potentially from a single IP) to exhaust VSZ and disrupt the service or other proxied conne...

CVE-2026-42006

CVE-2026-42006 affects Dovecot IMAP servers; the issue is uncontrolled memory usage caused by excessive bracing over IMAP, arising from an incomplete fix to CVE-2026-27857. Public advisories across multiple distros (Debian, Ubuntu, Fedora, SUSE) document vulnerable dovecot packages and partial/ne...

CVE-2026-0394

Dovecot is affected when per-domain passwd files are configured and placed one path component above /etc, or when a slash is added to allowed characters, allowing path traversal via a domain component that is a directory partial. This can enable reading /etc/passwd (or other paths ending with pas...

CVE-2025-59028

CVE-2025-59028 affects Dovecot’s authentication path where invalid base64 SASL data can disconnect from the auth server, causing DoS of concurrent logins. Public advisories (openSUSE/SUSE openSUSE:20554-1, SLES16 SUSE-SU-2026:21208-1, Ubuntu USN-8136-1) indicate the issue in the dovecot24 package...

CVE-2025-59032

CVE-2025-59032 affects ManageSieve: the AUTHENTICATE command crashes when a literal is used as the SASL initial response, potentially making the ManageSieve service unavailable for other users. Practical impact is availability denial of the service. Remediation provided in the entry is to upgrade...

CVE-2026-27860

CVE-2026-27860 describes an LDAP query injection in Dovecot when auth_username_chars is configured empty. The issue can potentially bypass restrictions and allow probing of LDAP structure. Multiple connected advisories acknowledge the vulnerability in Dovecot 2.4.x and specify fixes/escapes: open...

CVE-2026-27856

CVE-2026-27856 concerns the doveadm credential verification path, where direct comparison enables a timing oracle to determine configured credentials. The issue affects the doveadm HTTP service component used by Open-Xchange-related deployments, enabling an attacker to infer credentials through t...

CVE-2026-27858

CVE-2026-27858 affects the managesieve component. An attacker can send a specially crafted message before authentication that causes managesieve to allocate a large amount of memory, and can force the managesieve-login process to become unavailable by repeated crashes. The practical impact is pot...

CVE-2025-59031

Summary of CVE-2025-59031 (Dovecot) : A script provided by Dovecot for text conversion mishandles zip-style attachments. This can allow an attacker to craft OOXML documents that cause unintended files to be indexed and end up in full-text search (FTS) indexes. The underlying impact is limited to ...

CVE-2026-27855

Dovecot OTP authentication is vulnerable to a replay attack under specific conditions: if auth cache is enabled and the username is altered in passdb, OTP credentials can be cached so that the same OTP response remains valid. An attacker who observes an OTP exchange can log in as the targeted use...

CVE-2026-33603

The CVE-2026-33603 affects Dovecot (and client) via a specially crafted base64 exchange to fake SCRAM TLS channel binding. Root cause: attacker positions between Dovecot and client to perform MITM, enabling eavesdropping. Impact: confidentiality and integrity of the conversation can be compromise...

CVE-2026-40020

CVE-2026-40020 affects dovecot via IMAP SETACL: an attacker can inject the "anyone" permission into a user’s dovecot-acl file even when imap_acl_allow_anyone=no, causing folders to be spammed to all users. Impact is limited to spamming, not unauthorized data access. Multiple vendors have referenc...

CVE-2026-27851

The CVE-2026-27851 issue affects openSUSE openSUSE Tumbleweed dovecot24-2.4.4-1.1. The root cause is when a safe filter is used with variable expansion, causing all following pipelines on the same string to be treated as safe, which can let unsafe data be unescaped. This can enable SQL and LDAP i...

CVE-2026-27859

The CVE-2026-27859 issue concerns LMTP processing of mail messages with excessive RFC 2231 MIME parameters, which can cause unusually high CPU usage in the mail delivery process. Affected systems are those that rely on LMTP for mail transfer; the underlying cause is the handling/parsing of RFC 22...

CVE-2026-40016

CVE-2026-40016: An attacker can upload a malicious Sieve script via ManageSieve (or local access) to bypass CPU time limits, potentially increasing allowed run time up to 130× the configured limit and degrading server performance. Affected component is the Sieve execution/ManageSieve handling; ro...