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Fedora 43 : dovecot (2026-693373747f)

🗓️ 03 Jun 2026 00:00:00Reported by TenableType 
nessus
 nessus
🔗 www.tenable.com👁 8 Views

Fedora 43 dovecot advisory lists CVEs including memory usage, channel binding bypass, IMAP spam, and privilege drops.

Related
Refs
Code
ReporterTitlePublishedViews
Family
ATTACKERKB
CVE-2026-33603
12 May 202613:28
attackerkb
ATTACKERKB
CVE-2026-27851
12 May 202613:28
attackerkb
ATTACKERKB
CVE-2026-40016
12 May 202613:28
attackerkb
ATTACKERKB
CVE-2026-27857
27 Mar 202608:10
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ATTACKERKB
CVE-2026-40020
12 May 202613:28
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ATTACKERKB
CVE-2026-42006
12 May 202613:28
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Tenable Nessus
Amazon Linux 2023 : dovecot, dovecot-devel, dovecot-mysql (ALAS2023-2026-1570)
13 Apr 202600:00
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Amazon Linux 2 : dovecot, --advisory ALAS2-2026-3252 (ALAS-2026-3252)
30 Apr 202600:00
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Alibaba Cloud Linux 3 : 0119: dovecot (ALINUX3-SA-2026:0119)
25 May 202600:00
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AlmaLinux 10 : dovecot (ALSA-2026:13498)
6 May 202600:00
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Rows per page
#%NASL_MIN_LEVEL 80900
##
# (C) Tenable, Inc.
##
# The descriptive text and package checks in this plugin were
# extracted from Fedora Security Advisory FEDORA-2026-693373747f
#

include('compat.inc');

if (description)
{
  script_id(318284);
  script_version("1.1");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/06/03");

  script_cve_id(
    "CVE-2026-27851",
    "CVE-2026-27857",
    "CVE-2026-33603",
    "CVE-2026-40016",
    "CVE-2026-40020",
    "CVE-2026-42006"
  );
  script_xref(name:"FEDORA", value:"2026-693373747f");

  script_name(english:"Fedora 43 : dovecot (2026-693373747f)");

  script_set_attribute(attribute:"synopsis", value:
"The remote Fedora host is missing one or more security updates.");
  script_set_attribute(attribute:"description", value:
"The remote Fedora 43 host has a package installed that is affected by multiple vulnerabilities as referenced in the
FEDORA-2026-693373747f advisory.

    * CVE-2026-27851: lib-var-expand: Safe filter marks all following pipelines safe.
    * CVE-2026-33603: auth: CRAM-SHA-*-PLUS channel binding could be faked.
      MITM attacker with a certificate trusted by the client could have
      bypassed the requirement for channel binding.
    * CVE-2026-40020: IMAP folders can be shared-spammed to everyone.
    * CVE-2026-42006: An attacker can cause uncontrolled memory usage with
      excessive bracing over IMAP. The fix in CVE-2026-27857 was incomplete.
    * indexer-worker, quota-status, script-login, program-client-local: Root
      privileges are now dropped permanently before serving requests.
    * indexer-worker: Default restart_request_count changed to 1 to work
      correctly after permanent root privilege drop.
    * lmtp: Add back service_extra_groups=$SET:default_internal_group that was
      incorrectly removed in v2.4.3.
    * master: inet_listener_reuse_port has been replaced by service_reuse_port.
      The new setting properly pre-creates all listener sockets at startup and
      assigns one unique socket per process. Using this allows evenly distributing
      incoming connections to login processes.


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

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version
number.");
  script_set_attribute(attribute:"see_also", value:"https://bodhi.fedoraproject.org/updates/FEDORA-2026-693373747f");
  script_set_attribute(attribute:"solution", value:
"Update the affected 1:dovecot package.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/C:C/I:C/A:N");
  script_set_cvss_temporal_vector("CVSS2#E:U/RL:OF/RC:C");
  script_set_cvss3_base_vector("CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:U/RL:O/RC:C");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2026-27851");

  script_set_attribute(attribute:"exploitability_ease", value:"No known exploits are available");
  script_set_attribute(attribute:"exploit_available", value:"false");

  script_set_attribute(attribute:"vuln_publication_date", value:"2026/03/27");
  script_set_attribute(attribute:"patch_publication_date", value:"2026/05/18");
  script_set_attribute(attribute:"plugin_publication_date", value:"2026/06/03");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:fedoraproject:fedora:43");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:fedoraproject:fedora:dovecot");
  script_set_attribute(attribute:"generated_plugin", value:"current");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_family(english:"Fedora Local Security Checks");

  script_copyright(english:"This script is Copyright (C) 2026 and is owned by Tenable, Inc. or an Affiliate thereof.");

  script_dependencies("ssh_get_info.nasl");
  script_require_keys("Host/local_checks_enabled", "Host/RedHat/release", "Host/RedHat/rpm-list");

  exit(0);
}


include('rpm2.inc');

if (!get_kb_item('Host/local_checks_enabled')) audit(AUDIT_LOCAL_CHECKS_NOT_ENABLED);
var os_product = get_kb_item('installed_os/local/SSH/0/product');
if (isnull(os_product) || 'Fedora' >!< os_product) audit(AUDIT_OS_NOT, 'Fedora');
var os_version = get_kb_item('installed_os/local/SSH/0/version');
if (isnull(os_version)) audit(AUDIT_UNKNOWN_APP_VER, 'Fedora');
if (! preg(pattern:"^43([^0-9]|$)", string:os_version)) audit(AUDIT_OS_NOT, 'Fedora 43', 'Fedora ' + os_version);

if (!get_kb_item('Host/RedHat/rpm-list')) audit(AUDIT_PACKAGE_LIST_MISSING);

var cpu = get_kb_item('Host/cpu');
if (isnull(cpu)) audit(AUDIT_UNKNOWN_ARCH);
if ('x86_64' >!< cpu && cpu !~ "^i[3-6]86$" && 's390' >!< cpu && 'aarch64' >!< cpu) audit(AUDIT_LOCAL_CHECKS_NOT_IMPLEMENTED, 'Fedora', cpu);

var constraints = [
  {
    'release': '43',
    'pkgs': [
      {'reference':'dovecot-2.4.4-1.fc43', 'rpm_spec_vers_cmp':TRUE, 'epoch':'1'}
    ]
  }
];

var os_release = get_one_kb_item('installed_os/local/SSH/0/release');
var os_sp = get_one_kb_item('Host/*/minor_release');

var flag = 0;
var reference;
var sp;
var _cpu;
var el_string;
var rpm_spec_vers_cmp;
var epoch;
var allowmaj;
var exists_check;
var cves;
foreach var constraint ( constraints ) {
  # Check that the target release is equal to the affected release
  if (!empty_or_null(constraint['release'])){
    if (constraint['release'] != os_release) continue;
  }
  if (!empty_or_null(constraint['sp'])){
    if (constraint['sp'] != os_sp) continue;
  }
  foreach var pkg ( constraint['pkgs'] ) {
    reference = NULL;
    sp = NULL;
    _cpu = NULL;
    el_string = NULL;
    rpm_spec_vers_cmp = NULL;
    epoch = NULL;
    allowmaj = NULL;
    exists_check = NULL;
    cves = NULL;
    if (!empty_or_null(pkg['reference'])) reference = pkg['reference'];
    if (!empty_or_null(pkg['sp'])) sp = pkg['sp'];
    if (!empty_or_null(pkg['cpu'])) _cpu = pkg['cpu'];
    if (!empty_or_null(pkg['el_string'])) el_string = pkg['el_string'];
    if (!empty_or_null(pkg['rpm_spec_vers_cmp'])) rpm_spec_vers_cmp = pkg['rpm_spec_vers_cmp'];
    if (!empty_or_null(pkg['epoch'])) epoch = pkg['epoch'];
    if (!empty_or_null(pkg['allowmaj'])) allowmaj = pkg['allowmaj'];
    if (!empty_or_null(pkg['exists_check'])) exists_check = pkg['exists_check'];
    if (!empty_or_null(pkg['cves'])) cves = pkg['cves'];
    if (reference &&
        ## (no known rpm to check OR known rpm_exists)
        (!exists_check || rpm_exists(rpm:exists_check)) &&
        rpm_check(sp:sp, cpu:_cpu, reference:reference, epoch:epoch, el_string:el_string, rpm_spec_vers_cmp:rpm_spec_vers_cmp, allowmaj:allowmaj, cves:cves)) flag++;
  }
}

if (flag)
{
  security_report_v4(
      port       : 0,
      severity   : SECURITY_HOLE,
      extra      : rpm_report_get()
  );
  exit(0);
}
else
{
  var tested = pkg_tests_get();
  if (tested) audit(AUDIT_PACKAGE_NOT_AFFECTED, tested);
  else audit(AUDIT_PACKAGE_NOT_INSTALLED, 'dovecot');
}

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03 Jun 2026 00:00Current
5.8Medium risk
Vulners AI Score5.8
CVSS 3.17.5 - 9.1
EPSS0.00667
SSVC
8