CVE-2026-27856

EUVD-2026-16565
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.
ProviderTypeBase ScoreAtk. VectorAtk. ComplexityPriv. RequiredVector
NISTPrimary
7.4 HIGH
NETWORK
HIGH
NONE
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N
Base Score
CVSS 3.x
EPSS Score
Percentile: 3%
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
not-affected
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
not-affected
xenial
not-affected
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