Vulnerability-Lookup

BDU:2026-10401 (CVE-2026-27856)

Vulnerability from fstec – Published: 2026-07-23 – Updated: 2026-09-17 – View on bdu.fstec.ru Fixed

Title

Уязвимость компонента doveadm почтового сервера Dovecot, позволяющая нарушителю получить несанкционированный доступ к защищаемой информации

Summary

Уязвимость компонента doveadm почтового сервера Dovecot связана с раскрытием информации на основании временных расхождений. Эксплуатация уязвимости может позволить нарушителю, действующему удаленно, получить несанкционированный доступ к защищаемой информации

Severity

5.4 (Medium) CVSS 2.0


                      
                        AV:N/AC:H/Au:N/C:C/I:N/A:N

5.9 (Medium) CVSS 3.1


                      
                        CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N

Class

Architecture vulnerability

Status

Confirmed by the vendor

Exploitation

Information gathering, Authentication bypass

Incidents

Being clarified

Remediation

Software update

CWE

CWE-208 - Утечка информации на основании временных расхождений
CWE-287 - Неправильная аутентификация

Aliases

CVE-2026-27856

References

13 references

URL
https://github.com/advisories/GHSA-mv3x-9fw3-qf38
https://access.redhat.com/errata/RHSA-2026:26564
https://access.redhat.com/security/cve/CVE-2026-27856
https://bugzilla.redhat.com/show_bug.cgi?id=2452171
https://documentation.open-xchange.com/dovecot/security/advisories/csaf/2026/ox…
https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-27856.json
https://ubuntu.com/security/CVE-2026-27856
https://access.redhat.com/security/cve/cve-2026-27856
https://redos.red-soft.ru/search/?iblock_id=24&q=CVE-2026-27856
https://cve.basealt.ru/tag/cve-2025-59031.html
https://altsp.su/obnovleniya-bezopasnosti/
https://wiki.astralinux.ru/astra-linux-se17-bulletin-2026-0820SE17
https://wiki.astralinux.ru/astra-linux-se47-bulletin-2026-0907SE47

Impacted products

6 products from 7 vendors

Vendors

Canonical Ltd., Red Hat, Inc., ООО «Ред Софт», ООО «РусБИТех-Астра», АО «ИВК», Timo Sirainen

Products

Ubuntu, Red Hat Enterprise Linux, РЕД ОС (запись в едином реестре российских программ №3751), Astra Linux Special Edition (запись в едином реестре российских программ №369), АЛЬТ СП 10, Dovecot

Versions

14.04 LTS (Ubuntu), 6 (Red Hat Enterprise Linux), 20.04 LTS (Ubuntu), 7.3 (РЕД ОС), 1.7 (Astra Linux Special Edition), 22.04 LTS (Ubuntu), 4.7 (Astra Linux Special Edition), - (АЛЬТ СП 10), 24.04 LTS (Ubuntu), 7 Extended Lifecycle Support (Red Hat Enterprise Linux), 8.0 (РЕД ОС), до 2.4.3 (Dovecot), до 2.3.22.1 (Dovecot), от 3.0.0 до 3.0.5 (Dovecot), от 3.1.0 до 3.1.4 (Dovecot)

Product types

Operating system, Network software

Platforms

Canonical Ltd. Ubuntu 14.04 LTS, Red Hat, Inc. Red Hat Enterprise Linux 6, Canonical Ltd. Ubuntu 20.04 LTS, ООО «Ред Софт» РЕД ОС 7.3 (запись в едином реестре российских программ №3751), ООО «РусБИТех-Астра» Astra Linux Special Edition 1.7 (запись в едином реестре российских программ №369), Canonical Ltd. Ubuntu 22.04 LTS, ООО «РусБИТех-Астра» Astra Linux Special Edition 4.7 ARM (запись в едином реестре российских программ №369), АО «ИВК» АЛЬТ СП 10 -, Canonical Ltd. Ubuntu 24.04 LTS, Inc. Red Hat Enterprise Linux 7 Extended Lifecycle Support, ООО «Ред Софт» РЕД ОС 8.0 (запись в едином реестре российских программ №3751)

Mitigations

Использование рекомендаций: Для Dovecot: https://documentation.open-xchange.com/dovecot/security/advisories/csaf/2026/oxdc-adv-2026-0001.json Для Ред ОС: https://redos.red-soft.ru/search/?iblock_id=24&q=CVE-2026-27856 Для программных продуктов Red Hat Inc.: https://access.redhat.com/security/cve/cve-2026-27856 Для Ubuntu: https://ubuntu.com/security/CVE-2026-27856 Для АЛЬТ СП 10: https://cve.basealt.ru/tag/cve-2025-59031.html Для ОС АЛЬТ СП 10: установка обновления из публичного репозитория программного средства: https://altsp.su/obnovleniya-bezopasnosti/ Для ОС Astra Linux: обновить пакет dovecot до 1:2.3.19.1+dfsg1-2.1+deb12u6.astra17+p4 или более высокой версии, используя рекомендации производителя: https://wiki.astralinux.ru/astra-linux-se17-bulletin-2026-0820SE17 Для ОС Astra Linux: обновить пакет dovecot до 1:2.3.19.1+dfsg1-2.1+deb12u6.astra17+p4 или более высокой версии, используя рекомендации производителя: https://wiki.astralinux.ru/astra-linux-se47-bulletin-2026-0907SE47

JSON

To clipboard

{
  "CVSS 2.0": "AV:N/AC:H/Au:N/C:C/I:N/A:N",
  "CVSS 3.0": "AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N",
  "CVSS 4.0": null,
  "remediation_\u0418\u0434\u0435\u043d\u0442\u0438\u0444\u0438\u043a\u0430\u0442\u043e\u0440": null,
  "remediation_\u041d\u0430\u0438\u043c\u0435\u043d\u043e\u0432\u0430\u043d\u0438\u0435": null,
  "\u0412\u0435\u043d\u0434\u043e\u0440 \u041f\u041e": "Canonical Ltd., Red Hat, Inc., \u041e\u041e\u041e \u00ab\u0420\u0435\u0434 \u0421\u043e\u0444\u0442\u00bb, \u041e\u041e\u041e \u00ab\u0420\u0443\u0441\u0411\u0418\u0422\u0435\u0445-\u0410\u0441\u0442\u0440\u0430\u00bb, \u0410\u041e \u00ab\u0418\u0412\u041a\u00bb, Timo Sirainen",
  "\u0412\u0435\u0440\u0441\u0438\u044f \u041f\u041e": "14.04 LTS (Ubuntu), 6 (Red Hat Enterprise Linux), 20.04 LTS (Ubuntu), 7.3 (\u0420\u0415\u0414 \u041e\u0421), 1.7 (Astra Linux Special Edition), 22.04 LTS (Ubuntu), 4.7 (Astra Linux Special Edition), - (\u0410\u041b\u042c\u0422 \u0421\u041f 10), 24.04 LTS (Ubuntu), 7 Extended Lifecycle Support (Red Hat Enterprise Linux), 8.0 (\u0420\u0415\u0414 \u041e\u0421), \u0434\u043e 2.4.3 (Dovecot), \u0434\u043e 2.3.22.1 (Dovecot), \u043e\u0442 3.0.0 \u0434\u043e 3.0.5 (Dovecot), \u043e\u0442 3.1.0 \u0434\u043e 3.1.4 (Dovecot)",
  "\u0412\u043e\u0437\u043c\u043e\u0436\u043d\u044b\u0435 \u043c\u0435\u0440\u044b \u043f\u043e \u0443\u0441\u0442\u0440\u0430\u043d\u0435\u043d\u0438\u044e": "\u0418\u0441\u043f\u043e\u043b\u044c\u0437\u043e\u0432\u0430\u043d\u0438\u0435 \u0440\u0435\u043a\u043e\u043c\u0435\u043d\u0434\u0430\u0446\u0438\u0439:\n\u0414\u043b\u044f Dovecot:\nhttps://documentation.open-xchange.com/dovecot/security/advisories/csaf/2026/oxdc-adv-2026-0001.json\n\n\u0414\u043b\u044f \u0420\u0435\u0434 \u041e\u0421:\nhttps://redos.red-soft.ru/search/?iblock_id=24\u0026q=CVE-2026-27856\n\n\u0414\u043b\u044f \u043f\u0440\u043e\u0433\u0440\u0430\u043c\u043c\u043d\u044b\u0445 \u043f\u0440\u043e\u0434\u0443\u043a\u0442\u043e\u0432 Red Hat Inc.:\nhttps://access.redhat.com/security/cve/cve-2026-27856\n\n\u0414\u043b\u044f Ubuntu:\nhttps://ubuntu.com/security/CVE-2026-27856\n\n\u0414\u043b\u044f \u0410\u041b\u042c\u0422 \u0421\u041f 10:\nhttps://cve.basealt.ru/tag/cve-2025-59031.html\n\n\u0414\u043b\u044f \u041e\u0421 \u0410\u041b\u042c\u0422 \u0421\u041f 10: \u0443\u0441\u0442\u0430\u043d\u043e\u0432\u043a\u0430 \u043e\u0431\u043d\u043e\u0432\u043b\u0435\u043d\u0438\u044f \u0438\u0437 \u043f\u0443\u0431\u043b\u0438\u0447\u043d\u043e\u0433\u043e \u0440\u0435\u043f\u043e\u0437\u0438\u0442\u043e\u0440\u0438\u044f \u043f\u0440\u043e\u0433\u0440\u0430\u043c\u043c\u043d\u043e\u0433\u043e \u0441\u0440\u0435\u0434\u0441\u0442\u0432\u0430: https://altsp.su/obnovleniya-bezopasnosti/\n\n\u0414\u043b\u044f \u041e\u0421 Astra Linux:\n\u043e\u0431\u043d\u043e\u0432\u0438\u0442\u044c \u043f\u0430\u043a\u0435\u0442 dovecot \u0434\u043e 1:2.3.19.1+dfsg1-2.1+deb12u6.astra17+p4 \u0438\u043b\u0438 \u0431\u043e\u043b\u0435\u0435 \u0432\u044b\u0441\u043e\u043a\u043e\u0439 \u0432\u0435\u0440\u0441\u0438\u0438, \u0438\u0441\u043f\u043e\u043b\u044c\u0437\u0443\u044f \u0440\u0435\u043a\u043e\u043c\u0435\u043d\u0434\u0430\u0446\u0438\u0438 \u043f\u0440\u043e\u0438\u0437\u0432\u043e\u0434\u0438\u0442\u0435\u043b\u044f: https://wiki.astralinux.ru/astra-linux-se17-bulletin-2026-0820SE17\n\n\u0414\u043b\u044f \u041e\u0421 Astra Linux:\n\u043e\u0431\u043d\u043e\u0432\u0438\u0442\u044c \u043f\u0430\u043a\u0435\u0442 dovecot \u0434\u043e 1:2.3.19.1+dfsg1-2.1+deb12u6.astra17+p4 \u0438\u043b\u0438 \u0431\u043e\u043b\u0435\u0435 \u0432\u044b\u0441\u043e\u043a\u043e\u0439 \u0432\u0435\u0440\u0441\u0438\u0438, \u0438\u0441\u043f\u043e\u043b\u044c\u0437\u0443\u044f \u0440\u0435\u043a\u043e\u043c\u0435\u043d\u0434\u0430\u0446\u0438\u0438 \u043f\u0440\u043e\u0438\u0437\u0432\u043e\u0434\u0438\u0442\u0435\u043b\u044f: https://wiki.astralinux.ru/astra-linux-se47-bulletin-2026-0907SE47",
  "\u0414\u0430\u0442\u0430 \u0432\u044b\u044f\u0432\u043b\u0435\u043d\u0438\u044f": "27.03.2026",
  "\u0414\u0430\u0442\u0430 \u043f\u043e\u0441\u043b\u0435\u0434\u043d\u0435\u0433\u043e \u043e\u0431\u043d\u043e\u0432\u043b\u0435\u043d\u0438\u044f": "17.09.2026",
  "\u0414\u0430\u0442\u0430 \u043f\u0443\u0431\u043b\u0438\u043a\u0430\u0446\u0438\u0438": "23.07.2026",
  "\u0418\u0434\u0435\u043d\u0442\u0438\u0444\u0438\u043a\u0430\u0442\u043e\u0440": "BDU:2026-10401",
  "\u0418\u0434\u0435\u043d\u0442\u0438\u0444\u0438\u043a\u0430\u0442\u043e\u0440\u044b \u0434\u0440\u0443\u0433\u0438\u0445 \u0441\u0438\u0441\u0442\u0435\u043c \u043e\u043f\u0438\u0441\u0430\u043d\u0438\u0439 \u0443\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u0438": "CVE-2026-27856",
  "\u0418\u043d\u0444\u043e\u0440\u043c\u0430\u0446\u0438\u044f \u043e\u0431 \u0443\u0441\u0442\u0440\u0430\u043d\u0435\u043d\u0438\u0438": "\u0423\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u044c \u0443\u0441\u0442\u0440\u0430\u043d\u0435\u043d\u0430",
  "\u041a\u043b\u0430\u0441\u0441 \u0443\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u0438": "\u0423\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u044c \u0430\u0440\u0445\u0438\u0442\u0435\u043a\u0442\u0443\u0440\u044b",
  "\u041d\u0430\u0437\u0432\u0430\u043d\u0438\u0435 \u041f\u041e": "Ubuntu, Red Hat Enterprise Linux, \u0420\u0415\u0414 \u041e\u0421 (\u0437\u0430\u043f\u0438\u0441\u044c \u0432 \u0435\u0434\u0438\u043d\u043e\u043c \u0440\u0435\u0435\u0441\u0442\u0440\u0435 \u0440\u043e\u0441\u0441\u0438\u0439\u0441\u043a\u0438\u0445 \u043f\u0440\u043e\u0433\u0440\u0430\u043c\u043c \u21163751), Astra Linux Special Edition (\u0437\u0430\u043f\u0438\u0441\u044c \u0432 \u0435\u0434\u0438\u043d\u043e\u043c \u0440\u0435\u0435\u0441\u0442\u0440\u0435 \u0440\u043e\u0441\u0441\u0438\u0439\u0441\u043a\u0438\u0445 \u043f\u0440\u043e\u0433\u0440\u0430\u043c\u043c \u2116369), \u0410\u041b\u042c\u0422 \u0421\u041f 10, Dovecot",
  "\u041d\u0430\u0438\u043c\u0435\u043d\u043e\u0432\u0430\u043d\u0438\u0435 \u041e\u0421 \u0438 \u0442\u0438\u043f \u0430\u043f\u043f\u0430\u0440\u0430\u0442\u043d\u043e\u0439 \u043f\u043b\u0430\u0442\u0444\u043e\u0440\u043c\u044b": "Canonical Ltd. Ubuntu 14.04 LTS , Red Hat, Inc. Red Hat Enterprise Linux 6 , Canonical Ltd. Ubuntu 20.04 LTS , \u041e\u041e\u041e \u00ab\u0420\u0435\u0434 \u0421\u043e\u0444\u0442\u00bb \u0420\u0415\u0414 \u041e\u0421 7.3  (\u0437\u0430\u043f\u0438\u0441\u044c \u0432 \u0435\u0434\u0438\u043d\u043e\u043c \u0440\u0435\u0435\u0441\u0442\u0440\u0435 \u0440\u043e\u0441\u0441\u0438\u0439\u0441\u043a\u0438\u0445 \u043f\u0440\u043e\u0433\u0440\u0430\u043c\u043c \u21163751), \u041e\u041e\u041e \u00ab\u0420\u0443\u0441\u0411\u0418\u0422\u0435\u0445-\u0410\u0441\u0442\u0440\u0430\u00bb Astra Linux Special Edition 1.7  (\u0437\u0430\u043f\u0438\u0441\u044c \u0432 \u0435\u0434\u0438\u043d\u043e\u043c \u0440\u0435\u0435\u0441\u0442\u0440\u0435 \u0440\u043e\u0441\u0441\u0438\u0439\u0441\u043a\u0438\u0445 \u043f\u0440\u043e\u0433\u0440\u0430\u043c\u043c \u2116369), Canonical Ltd. Ubuntu 22.04 LTS , \u041e\u041e\u041e \u00ab\u0420\u0443\u0441\u0411\u0418\u0422\u0435\u0445-\u0410\u0441\u0442\u0440\u0430\u00bb Astra Linux Special Edition 4.7 ARM (\u0437\u0430\u043f\u0438\u0441\u044c \u0432 \u0435\u0434\u0438\u043d\u043e\u043c \u0440\u0435\u0435\u0441\u0442\u0440\u0435 \u0440\u043e\u0441\u0441\u0438\u0439\u0441\u043a\u0438\u0445 \u043f\u0440\u043e\u0433\u0440\u0430\u043c\u043c \u2116369), \u0410\u041e \u00ab\u0418\u0412\u041a\u00bb \u0410\u041b\u042c\u0422 \u0421\u041f 10 - , Canonical Ltd. Ubuntu 24.04 LTS , Red Hat, Inc. Red Hat Enterprise Linux 7 Extended Lifecycle Support , \u041e\u041e\u041e \u00ab\u0420\u0435\u0434 \u0421\u043e\u0444\u0442\u00bb \u0420\u0415\u0414 \u041e\u0421 8.0  (\u0437\u0430\u043f\u0438\u0441\u044c \u0432 \u0435\u0434\u0438\u043d\u043e\u043c \u0440\u0435\u0435\u0441\u0442\u0440\u0435 \u0440\u043e\u0441\u0441\u0438\u0439\u0441\u043a\u0438\u0445 \u043f\u0440\u043e\u0433\u0440\u0430\u043c\u043c \u21163751)",
  "\u041d\u0430\u0438\u043c\u0435\u043d\u043e\u0432\u0430\u043d\u0438\u0435 \u0443\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u0438": "\u0423\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u044c \u043a\u043e\u043c\u043f\u043e\u043d\u0435\u043d\u0442\u0430 doveadm \u043f\u043e\u0447\u0442\u043e\u0432\u043e\u0433\u043e \u0441\u0435\u0440\u0432\u0435\u0440\u0430 Dovecot, \u043f\u043e\u0437\u0432\u043e\u043b\u044f\u044e\u0449\u0430\u044f \u043d\u0430\u0440\u0443\u0448\u0438\u0442\u0435\u043b\u044e \u043f\u043e\u043b\u0443\u0447\u0438\u0442\u044c \u043d\u0435\u0441\u0430\u043d\u043a\u0446\u0438\u043e\u043d\u0438\u0440\u043e\u0432\u0430\u043d\u043d\u044b\u0439 \u0434\u043e\u0441\u0442\u0443\u043f \u043a \u0437\u0430\u0449\u0438\u0449\u0430\u0435\u043c\u043e\u0439 \u0438\u043d\u0444\u043e\u0440\u043c\u0430\u0446\u0438\u0438",
  "\u041d\u0430\u043b\u0438\u0447\u0438\u0435 \u044d\u043a\u0441\u043f\u043b\u043e\u0439\u0442\u0430": "\u0414\u0430\u043d\u043d\u044b\u0435 \u0443\u0442\u043e\u0447\u043d\u044f\u044e\u0442\u0441\u044f",
  "\u041e\u043f\u0438\u0441\u0430\u043d\u0438\u0435 \u043e\u0448\u0438\u0431\u043a\u0438 CWE": "\u0423\u0442\u0435\u0447\u043a\u0430 \u0438\u043d\u0444\u043e\u0440\u043c\u0430\u0446\u0438\u0438 \u043d\u0430 \u043e\u0441\u043d\u043e\u0432\u0430\u043d\u0438\u0438 \u0432\u0440\u0435\u043c\u0435\u043d\u043d\u044b\u0445 \u0440\u0430\u0441\u0445\u043e\u0436\u0434\u0435\u043d\u0438\u0439 (CWE-208), \u041d\u0435\u043f\u0440\u0430\u0432\u0438\u043b\u044c\u043d\u0430\u044f \u0430\u0443\u0442\u0435\u043d\u0442\u0438\u0444\u0438\u043a\u0430\u0446\u0438\u044f (CWE-287)",
  "\u041e\u043f\u0438\u0441\u0430\u043d\u0438\u0435 \u0443\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u0438": "\u0423\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u044c \u043a\u043e\u043c\u043f\u043e\u043d\u0435\u043d\u0442\u0430 doveadm \u043f\u043e\u0447\u0442\u043e\u0432\u043e\u0433\u043e \u0441\u0435\u0440\u0432\u0435\u0440\u0430 Dovecot \u0441\u0432\u044f\u0437\u0430\u043d\u0430 \u0441 \u0440\u0430\u0441\u043a\u0440\u044b\u0442\u0438\u0435\u043c \u0438\u043d\u0444\u043e\u0440\u043c\u0430\u0446\u0438\u0438 \u043d\u0430 \u043e\u0441\u043d\u043e\u0432\u0430\u043d\u0438\u0438 \u0432\u0440\u0435\u043c\u0435\u043d\u043d\u044b\u0445 \u0440\u0430\u0441\u0445\u043e\u0436\u0434\u0435\u043d\u0438\u0439. \u042d\u043a\u0441\u043f\u043b\u0443\u0430\u0442\u0430\u0446\u0438\u044f \u0443\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u0438 \u043c\u043e\u0436\u0435\u0442 \u043f\u043e\u0437\u0432\u043e\u043b\u0438\u0442\u044c \u043d\u0430\u0440\u0443\u0448\u0438\u0442\u0435\u043b\u044e, \u0434\u0435\u0439\u0441\u0442\u0432\u0443\u044e\u0449\u0435\u043c\u0443 \u0443\u0434\u0430\u043b\u0435\u043d\u043d\u043e, \u043f\u043e\u043b\u0443\u0447\u0438\u0442\u044c \u043d\u0435\u0441\u0430\u043d\u043a\u0446\u0438\u043e\u043d\u0438\u0440\u043e\u0432\u0430\u043d\u043d\u044b\u0439 \u0434\u043e\u0441\u0442\u0443\u043f \u043a \u0437\u0430\u0449\u0438\u0449\u0430\u0435\u043c\u043e\u0439 \u0438\u043d\u0444\u043e\u0440\u043c\u0430\u0446\u0438\u0438",
  "\u041f\u043e\u0441\u043b\u0435\u0434\u0441\u0442\u0432\u0438\u044f \u044d\u043a\u0441\u043f\u043b\u0443\u0430\u0442\u0430\u0446\u0438\u0438 \u0443\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u0438": null,
  "\u041f\u0440\u043e\u0447\u0430\u044f \u0438\u043d\u0444\u043e\u0440\u043c\u0430\u0446\u0438\u044f": null,
  "\u0421\u0432\u044f\u0437\u044c \u0441 \u0438\u043d\u0446\u0438\u0434\u0435\u043d\u0442\u0430\u043c\u0438 \u0418\u0411": "\u0414\u0430\u043d\u043d\u044b\u0435 \u0443\u0442\u043e\u0447\u043d\u044f\u044e\u0442\u0441\u044f",
  "\u0421\u043e\u0441\u0442\u043e\u044f\u043d\u0438\u0435 \u0443\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u0438": "\u041e\u043f\u0443\u0431\u043b\u0438\u043a\u043e\u0432\u0430\u043d\u0430",
  "\u0421\u043f\u043e\u0441\u043e\u0431 \u0443\u0441\u0442\u0440\u0430\u043d\u0435\u043d\u0438\u044f": "\u041e\u0431\u043d\u043e\u0432\u043b\u0435\u043d\u0438\u0435 \u043f\u0440\u043e\u0433\u0440\u0430\u043c\u043c\u043d\u043e\u0433\u043e \u043e\u0431\u0435\u0441\u043f\u0435\u0447\u0435\u043d\u0438\u044f",
  "\u0421\u043f\u043e\u0441\u043e\u0431 \u044d\u043a\u0441\u043f\u043b\u0443\u0430\u0442\u0430\u0446\u0438\u0438": "\u041d\u0435\u0441\u0430\u043d\u043a\u0446\u0438\u043e\u043d\u0438\u0440\u043e\u0432\u0430\u043d\u043d\u044b\u0439 \u0441\u0431\u043e\u0440 \u0438\u043d\u0444\u043e\u0440\u043c\u0430\u0446\u0438\u0438, \u041d\u0430\u0440\u0443\u0448\u0435\u043d\u0438\u0435 \u0430\u0443\u0442\u0435\u043d\u0442\u0438\u0444\u0438\u043a\u0430\u0446\u0438\u0438",
  "\u0421\u0441\u044b\u043b\u043a\u0438 \u043d\u0430 \u0438\u0441\u0442\u043e\u0447\u043d\u0438\u043a\u0438": "https://github.com/advisories/GHSA-mv3x-9fw3-qf38\nhttps://access.redhat.com/errata/RHSA-2026:26564\nhttps://access.redhat.com/security/cve/CVE-2026-27856\nhttps://bugzilla.redhat.com/show_bug.cgi?id=2452171\nhttps://documentation.open-xchange.com/dovecot/security/advisories/csaf/2026/oxdc-adv-2026-0001.json\nhttps://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-27856.json\nhttps://ubuntu.com/security/CVE-2026-27856\nhttps://access.redhat.com/security/cve/cve-2026-27856\nhttps://redos.red-soft.ru/search/?iblock_id=24\u0026q=CVE-2026-27856\nhttps://cve.basealt.ru/tag/cve-2025-59031.html\nhttps://altsp.su/obnovleniya-bezopasnosti/\nhttps://wiki.astralinux.ru/astra-linux-se17-bulletin-2026-0820SE17\nhttps://wiki.astralinux.ru/astra-linux-se47-bulletin-2026-0907SE47",
  "\u0421\u0442\u0430\u0442\u0443\u0441 \u0443\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u0438": "\u041f\u043e\u0434\u0442\u0432\u0435\u0440\u0436\u0434\u0435\u043d\u0430 \u043f\u0440\u043e\u0438\u0437\u0432\u043e\u0434\u0438\u0442\u0435\u043b\u0435\u043c",
  "\u0422\u0438\u043f \u041f\u041e": "\u041e\u043f\u0435\u0440\u0430\u0446\u0438\u043e\u043d\u043d\u0430\u044f \u0441\u0438\u0441\u0442\u0435\u043c\u0430, \u0421\u0435\u0442\u0435\u0432\u043e\u0435 \u043f\u0440\u043e\u0433\u0440\u0430\u043c\u043c\u043d\u043e\u0435 \u0441\u0440\u0435\u0434\u0441\u0442\u0432\u043e",
  "\u0422\u0438\u043f \u043e\u0448\u0438\u0431\u043a\u0438 CWE": "CWE-208, CWE-287",
  "\u0423\u0440\u043e\u0432\u0435\u043d\u044c \u043e\u043f\u0430\u0441\u043d\u043e\u0441\u0442\u0438 \u0443\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u0438": "\u0421\u0440\u0435\u0434\u043d\u0438\u0439 \u0443\u0440\u043e\u0432\u0435\u043d\u044c \u043e\u043f\u0430\u0441\u043d\u043e\u0441\u0442\u0438 (\u0431\u0430\u0437\u043e\u0432\u0430\u044f \u043e\u0446\u0435\u043d\u043a\u0430 CVSS 2.0 \u0441\u043e\u0441\u0442\u0430\u0432\u043b\u044f\u0435\u0442 5,4)\n\u0421\u0440\u0435\u0434\u043d\u0438\u0439 \u0443\u0440\u043e\u0432\u0435\u043d\u044c \u043e\u043f\u0430\u0441\u043d\u043e\u0441\u0442\u0438 (\u0431\u0430\u0437\u043e\u0432\u0430\u044f \u043e\u0446\u0435\u043d\u043a\u0430 CVSS 3.1 \u0441\u043e\u0441\u0442\u0430\u0432\u043b\u044f\u0435\u0442 5,9)"
}

CVE-2026-27856 (GCVE-0-2026-27856)

Vulnerability from cvelistv5 – Published: 2026-03-27 08:10 – Updated: 2026-07-15 01:12

Summary

Doveadm credentials are verified using direct comparison which is susceptible to timing oracle attack. An attacker can use this to determine the configured credentials. Figuring out the credential will lead into full access to the affected component. Limit access to the doveadm http service port, install fixed version. No publicly available exploits are known.

Severity

7.4 (High)


                        
                          CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N

SSVC

Exploitation: none Automatable: no Technical Impact: total

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-03-27 13:21 UTC

CWE

CWE-287 - Improper Authentication
CWE-208 - Observable Timing Discrepancy

Assigner

OX mitre root

References

5 references

URL	Tags
https://documentation.open-xchange.com/dovecot/se…	vendor-advisory
https://access.redhat.com/security/cve/CVE-2026-27856	vdb-entryx_refsource_REDHAT
https://bugzilla.redhat.com/show_bug.cgi?id=2452171	issue-trackingx_refsource_REDHAT
https://security.access.redhat.com/data/csaf/v2/v…	x_sadp-csaf-vex
https://access.redhat.com/errata/RHSA-2026:26564	vendor-advisoryx_refsource_REDHAT

Impacted products

6 products

Vendor	Product	Version
Open-Xchange GmbH	OX Dovecot Pro	Affected: 0 , ≤ 2.3.0 (semver)
Red Hat	Red Hat Enterprise Linux 7 Extended Lifecycle Support	Unaffected: 1:2.2.36-8.el7_9.1 , < * (rpm) cpe:/o:redhat:rhel_els:7
Red Hat	Red Hat Enterprise Linux 10	cpe:/o:redhat:enterprise_linux:10
Red Hat	Red Hat Enterprise Linux 6	cpe:/o:redhat:enterprise_linux:6
Red Hat	Red Hat Enterprise Linux 8	cpe:/o:redhat:enterprise_linux:8
Red Hat	Red Hat Enterprise Linux 9	cpe:/o:redhat:enterprise_linux:9

Show details on NVD website

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}

Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.

Related by attack behaviour

Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.

Action not permitted

BDU:2026-10401 (CVE-2026-27856)

CVE-2026-27856 (GCVE-0-2026-27856)

Tags

Sightings

Nomenclature

Related by attack behaviour