CVE-2026-27858

EUVD-2026-16569
Attacker can send a specifically crafted message before authentication that causes managesieve to allocate large amount of memory.
 Attacker can force managesieve-login to be unavailable by repeatedly crashing the process. Protect access to managesieve protocol, or install fixed version. No publicly available exploits are known.
ProviderTypeBase ScoreAtk. VectorAtk. ComplexityPriv. RequiredVector
NISTPrimary
7.5 HIGH
NETWORK
LOW
NONE
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Base Score
CVSS 3.x
EPSS Score
Percentile: 6%
Affected Products (NVD)
VendorProductVersion
dovecotdovecot
𝑥
< 2.4.3
open-xchangedovecot
𝑥
< 2.3.22.1
open-xchangedovecot
3.0.0 ≤
𝑥
< 3.0.5
open-xchangedovecot
3.1.0 ≤
𝑥
< 3.1.4
𝑥
= Vulnerable software versions
Debian logo
Debian Releases
Debian Product
Codename
dovecot
bookworm
vulnerable
bookworm (security)
1:2.3.19.1+dfsg1-2.1+deb12u4
fixed
bullseye
vulnerable
bullseye (security)
1:2.3.13+dfsg1-2+deb11u3
fixed
forky
1:2.4.3+dfsg1-2
fixed
sid
1:2.4.3+dfsg1-2
fixed
trixie
vulnerable
trixie (security)
1:2.4.1+dfsg1-6+deb13u4
fixed
Ubuntu logo
Ubuntu Releases
Ubuntu Product
Codename
dovecot
bionic
needed
focal
needed
jammy
Fixed 1:2.3.16+dfsg1-3ubuntu2.7
released
noble
Fixed 1:2.3.21+dfsg1-2ubuntu6.3
released
questing
Fixed 1:2.4.1+dfsg1-5ubuntu4.1
released
resolute
not-affected
trusty
needed
xenial
needed
openSUSE logo
openSUSE / SLES Releases
openSUSE Product
Release
dovecot22
suse enterprise server 12 SP3
2.2.31-19.32.1
fixed
suse enterprise server 12 SP5
2.2.31-19.32.1
fixed
dovecot22-backend-mysql
suse enterprise server 12 SP3
2.2.31-19.32.1
fixed
suse enterprise server 12 SP5
2.2.31-19.32.1
fixed
dovecot22-backend-pgsql
suse enterprise server 12 SP3
2.2.31-19.32.1
fixed
suse enterprise server 12 SP5
2.2.31-19.32.1
fixed
dovecot22-backend-sqlite
suse enterprise server 12 SP3
2.2.31-19.32.1
fixed
suse enterprise server 12 SP5
2.2.31-19.32.1
fixed
dovecot22-devel
suse enterprise server 12 SP5
2.2.31-19.32.1
fixed
Red Hat logo
Red Hat Enterprise Linux Releases
Red Hat Product
Release
dovecot
RHEL 8
1:2.3.16-7.el8_10
fixed
RHEL 9
1:2.3.16-15.el9_7.1
fixed
dovecot-devel
RHEL 8
1:2.3.16-7.el8_10
fixed
RHEL 9
1:2.3.16-15.el9_7.1
fixed
dovecot-mysql
RHEL 8
1:2.3.16-7.el8_10
fixed
RHEL 9
1:2.3.16-15.el9_7.1
fixed
dovecot-pgsql
RHEL 8
1:2.3.16-7.el8_10
fixed
RHEL 9
1:2.3.16-15.el9_7.1
fixed
dovecot-pigeonhole
RHEL 8
1:2.3.16-7.el8_10
fixed
RHEL 9
1:2.3.16-15.el9_7.1
fixed
Common Weakness Enumeration
Vulnerability Media Exposure
References
https://documentation.open-xchange.com/dovecot/security/advisories/csaf/2026/oxdc-adv-2026-0001.json