7.5

CVE-2026-27857

Sending "NOOP (((...)))" command with 4000 parenthesis open+close results in ~1MB extra memory usage. Longer commands will result in client disconnection. This 1 MB can be left allocated for longer time periods by not sending the command ending LF. So attacker could connect possibly from even a single IP and create 1000 connections to allocate 1 GB of memory, which would likely result in reaching VSZ limit and killing the process and its other proxied connections. Attacker could connect possibly from even a single IP and create 1000 connections to allocate 1 GB of memory, which would likely result in reaching VSZ limit and killing the process and its other proxied connections. Install fixed version, there is no other remediation. No publicly available exploits are known.
Daten sind bereitgestellt durch National Vulnerability Database (NVD)
Dovecot ≫ Dovecot Version < 2.4.3
Open-xchange ≫ Dovecot SwEditionpro Version < 2.3.22.1
Open-xchange ≫ Dovecot SwEditionpro Version >= 3.0.0 < 3.0.5
Open-xchange ≫ Dovecot SwEditionpro Version >= 3.1.0 < 3.1.4
Zu dieser CVE wurde keine Warnung gefunden.
EPSS Metriken
Typ Quelle Score Percentile
EPSS FIRST.org 0.67% 0.472
CVSS Metriken
Quelle Base Score Exploit Score Impact Score Vector String
nvd@nist.gov 7.5 3.9 3.6
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
security@open-xchange.com 4.3 2.8 1.4
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L
0b0ca135-0b70-47e7-9f44-1890c2a1c46c 7.5 3.9 3.6
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CWE-400 Uncontrolled Resource Consumption

The product does not properly control the allocation and maintenance of a limited resource.

CWE-770 Allocation of Resources Without Limits or Throttling

The product allocates a reusable resource or group of resources on behalf of an actor without imposing any intended restrictions on the size or number of resources that can be allocated.

https://documentation.open-xchange.com/dovecot/security/advisories/csaf/2026/oxdc-adv-2026-0001.json
Vendor Advisory
https://access.redhat.com/errata/RHSA-2026:13498
https://access.redhat.com/errata/RHSA-2026:13830
https://access.redhat.com/errata/RHSA-2026:13857
https://access.redhat.com/errata/RHSA-2026:17602
https://access.redhat.com/errata/RHSA-2026:17625
https://access.redhat.com/errata/RHSA-2026:17626
https://access.redhat.com/errata/RHSA-2026:17628
https://access.redhat.com/errata/RHSA-2026:17630
https://access.redhat.com/errata/RHSA-2026:18053
https://access.redhat.com/errata/RHSA-2026:19149
https://access.redhat.com/errata/RHSA-2026:19364
https://access.redhat.com/errata/RHSA-2026:19453
https://access.redhat.com/errata/RHSA-2026:19455
https://access.redhat.com/errata/RHSA-2026:26564
https://access.redhat.com/security/cve/CVE-2026-27857
https://bugzilla.redhat.com/show_bug.cgi?id=2452179
https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-27857.json