CVE-2026-27856
7.4
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N
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.
Affected Software
| Vendor | Product | Version Range | Status |
|---|---|---|---|
| Open-Xchange GmbH | OX Dovecot Pro | 0 <= 2.3.0 | affected |
Weaknesses
- CWE-287: Improper Authentication
ADP Enrichment
CISA ADP Vulnrichment
- SSVC:
- Exploitation: none
- Automatable: no
- Technical Impact: total
dovecot: Doveadm: Full access via timing oracle attack in credential verification
Additional References
- https://access.redhat.com/security/cve/CVE-2026-27856
- https://bugzilla.redhat.com/show_bug.cgi?id=2452171
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-27856.json
- https://access.redhat.com/errata/RHSA-2026:26564
References
- https://documentation.open-xchange.com/dovecot/security/advisories/csaf/2026/oxdc-adv-2026-0001.json
Feedback
Was this page helpful?
Glad to hear it! Please tell us how we can improve.
Sorry to hear that. Please tell us how we can improve.