The remote Debian 11 host has packages installed that are affected by multiple vulnerabilities as referenced in the dla-4556 advisory.

    -------------------------------------------------------------------------     Debian LTS Advisory DLA-4556-1                debian-lts@lists.debian.org     https://www.debian.org/lts/security/                       Guilhem Moulin     May 01, 2026                                  https://wiki.debian.org/LTS
    -------------------------------------------------------------------------

    Package        : dovecot     Version        : 1:2.3.13+dfsg1-2+deb11u3     CVE ID         : CVE-2025-59031 CVE-2025-59032 CVE-2026-0394 CVE-2026-27855                      CVE-2026-27856 CVE-2026-27857 CVE-2026-27858 CVE-2026-27859

    Multiple vulnerabilities were discovered in dovecot, a POP3/IMAP server,     which could lead to Denial of Service, information leak, path traversal,     authentication bypass, replay attacks or timing side channel attacks.

    CVE-2025-59031

        The decode2text.sh example script, which was installed into         dovecot-core/examples, was found handle zip-style attachment in an         unsafe manner.  In particular, OOXML extraction may follow symlinks         and read unintended files during indexing.  The script is no longer         installed.

    CVE-2025-59032

        It was found that the ManageSieve AUTHENTICATE command crashes the         ManageSieve service when using literal as SASL initial response,         leading to Denial of Service.

    CVE-2026-0394

        A pass traversal vulnerability was discovered in the passwd-file         passdb/userdb when dovecot has been configured to use per-domain         passwd files, allowing inadvertently reading /etc/passwd in some         situations.  If this file contains passwords, it can be used to         authenticate wrongly, or if this is userdb, it can incorrectly make         system users appear valid users.

    CVE-2026-27855

        The OTP authentication driver was found to be vulnerable to replay         attack if auth cache is enabled the and username is altered in         passdb.  An attacker able to observe an OTP exchange is therefore         able to impersonate the user.

    CVE-2026-27856

        Doveadm credentials were not checked using timing-safe checking         functions.  An attacker can exploit this issue to discover configured         credentials, leading into full access to the affected component.

    CVE-2026-27857

        It was discovered that sending excessive parenthesis caused the         imap-login process to use excessive memory, leading to Denial of         Service.

    CVE-2026-27858

        It was discovered that the managesieve-login process could allocate         large amount of memory during authentication via specifically crafted         message, leading to Denial of Service.

    CVE-2026-27859

        It was discovered that excessive RFC 2231 MIME parameters in email         would cause excessive CPU usage, which could lead to Denial of         Service.  Dovecot now limits the number of parameters to process.

    For Debian 11 bullseye, these problems have been fixed in version     1:2.3.13+dfsg1-2+deb11u3.

    We recommend that you upgrade your dovecot packages.

    For the detailed security status of dovecot please refer to     its security tracker page at:
    https://security-tracker.debian.org/tracker/dovecot

    Further information about Debian LTS security advisories, how to apply     these updates to your system and frequently asked questions can be     found at: https://wiki.debian.org/LTS     Attachment:
    signature.asc     Description: PGP signature

Tenable has extracted the preceding description block directly from the Debian security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available.

  - When dovecot has been configured to use per-domain passwd files, and they are placed one path component     above /etc, or slash has been added to allowed characters, path traversal can happen if the domain     component is directory partial. This allows inadvertently reading /etc/passwd (or some other path which     ends with passwd). If this file contains passwords, it can be used to authenticate wrongly, or if this is     userdb, it can unexpectly make system users appear valid users. Upgrade to fixed version, or use different     authentication scheme that does not rely on paths. Alternatively you can also ensure that the per-domain     passwd files are in some other location, such as /etc/dovecot/auth/%d. No publicly available exploits are     known. (CVE-2026-0394)

Note that Nessus relies on the presence of the package as reported by the vendor.

The remote Debian 12 host has packages installed that are affected by multiple vulnerabilities as referenced in the dsa-6197 advisory.

    - -------------------------------------------------------------------------     Debian Security Advisory DSA-6197-1                   security@debian.org     https://www.debian.org/security/                       Moritz Muehlenhoff     April 05, 2026                        https://www.debian.org/security/faq
    - -------------------------------------------------------------------------

    Package        : dovecot     CVE ID         : CVE-2025-59031 CVE-2025-59032 CVE-2026-27855                      CVE-2026-27856 CVE-2026-27857 CVE-2026-27858                      CVE-2026-27859 CVE-2026-59028 CVE-2026-24031                      CVE-2026-27860 CVE-2026-0394

    Multiple vulnerabilities have been discovered in the Dovecot IMAP server     which way result in denial of service, SQL injection, path traversal,     replay attacks or timing side channel attacks.

    For the oldstable distribution (bookworm), these problems have been fixed     in version 1:2.3.19.1+dfsg1-2.1+deb12u2.

    For the stable distribution (trixie), these problems have been fixed in     version 1:2.4.1+dfsg1-6+deb13u4.

    We recommend that you upgrade your dovecot packages.

    For the detailed security status of dovecot please refer to     its security tracker page at:
    https://security-tracker.debian.org/tracker/dovecot

    Further information about Debian Security Advisories, how to apply     these updates to your system and frequently asked questions can be     found at: https://www.debian.org/security/

    Mailing list: debian-security-announce@lists.debian.org

Tenable has extracted the preceding description block directly from the Debian security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

The remote Ubuntu 22.04 LTS / 24.04 LTS / 25.10 host has packages installed that are affected by multiple vulnerabilities as referenced in the USN-8136-1 advisory.

    It was discovered that Dovecot incorrectly handled invalid base64 SASL data. An attacker could possibly     use this issue to cause a denial of service. This issue only affected Ubuntu 25.10. (CVE-2025-59028)

    It was discovered that Dovecot script decode2text.sh incorrectly handled zip files. An attacker could     possibly use this issue to obtain sensitive information. (CVE-2025-59031)

    It was discovered that Dovecot incorrectly handled certain AUTHENTICATE requests. An attacker could     possibly use this issue to cause a denial of service. (CVE-2025-59032)

    It was discovered that Dovecot incorrectly handled certain SQL based authentication. An attacker could     possibly use this issue to bypass authentication. This issue only affected Ubuntu 25.10. (CVE-2026-24031)

    It was discovered that Dovecot incorrectly handled certain LDAP based authentication. An attacker could     possibly use this issue to bypass restrictions and allow probing of LDAP structure. This issue only     affected Ubuntu 25.10. (CVE-2026-27860)

    It was discovered that Dovecot is vulnerable to replay attack under certain conditions. An attacker could     possibly use this issue to bypass authentication. (CVE-2026-27855)

    It was discovered that Dovecot is vulnerable to a timing attack under certain conditions. An attacker     could possibly use this issue to bypass authentication. (CVE-2026-27856)

    It was discovered that Dovecot incorrectly handled certain IMAP login requests. An attacker could possibly     use this issue to cause a denial of service. (CVE-2026-27857)

    It was discovered that Dovecot incorrectly handled certain specially crafted messages. An attacker could     possibly use this issue to cause a denial of service. (CVE-2026-27858)

    It was discovered that Dovecot incorrectly handled certain specially crafted mail messages. An attacker     could possibly use this issue to cause a denial of service. (CVE-2026-27859)

    It was discovered that Dovecot incorrectly handles file paths. A attacker could possibly use this issue to     perform a path traversal and obtain or modify arbitrary files. This issue only affected Ubuntu 22.04 LTS     and Ubuntu 24.04 LTS. (CVE-2026-0394)

Tenable has extracted the preceding description block directly from the Ubuntu security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

ID	Name	Product	Family	Published	Updated	Severity
321107	Debian dla-4556 : dovecot-auth-lua - security update	Nessus	Debian Local Security Checks	6/15/2026	6/15/2026	medium
304062	Linux Distros Unpatched Vulnerability : CVE-2026-0394	Nessus	Misc.	3/28/2026	8/2/2026	medium
305037	Debian dsa-6197 : dovecot-auth-lua - security update	Nessus	Debian Local Security Checks	4/5/2026	5/19/2026	high
304437	Ubuntu 22.04 LTS / 24.04 LTS / 25.10 : Dovecot vulnerabilities (USN-8136-1)	Nessus	Ubuntu Local Security Checks	3/31/2026	4/20/2026	high

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