CVE-2026-27856
21Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 7.4epss 0.4%
exploitation probability
0.4%top 68% of all CVEs
observed exploitation
nono source reports it
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.
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N
Affected products
Open-Xchange GmbH · OX Dovecot ProReferences
https://access.redhat.com/errata/RHSA-2026:26564https://access.redhat.com/security/cve/CVE-2026-27856https://bugzilla.redhat.com/show_bug.cgi?id=2452171https://documentation.open-xchange.com/dovecot/security/advisories/csaf/2026/oxdc-adv-2026-0001.jsonhttps://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-27856.json