CVE-2026-27856
High
Description
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.
SeverityHigh
CVSS7.4
Exploit probability—
ProductDovecot
PublishedMar 27, 2026
First seenMar 27, 2026
Weakness typeCWE-287Improper authentication
How to fix
Update
- dovecot dovecot2.4.3 or later
- open-xchange dovecot2.3.22.1, 3.0.5, 3.1.4 or later
Affected products
| Product | Affected versions | Fixed in |
|---|---|---|
| dovecot dovecot | v < 2.4.3 | 2.4.3 |
| open-xchange dovecot | v < 2.3.22.1, 3.0.0 ≤ v < 3.0.5, 3.1.0 ≤ v < 3.1.4 | 2.3.22.1, 3.0.5, 3.1.4 |
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