Bug 2525568 (CVE-2026-42393)

Summary: CVE-2026-42393 dovecot: Dovecot: Information disclosure via timing attack on `doveadm` password/API key comparison
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
Status: NEW --- QA Contact:
Severity: low Docs Contact:
Priority: low    
Version: unspecifiedCC: rhel-process-autobot, watson-tool-maintainers
Target Milestone: ---Keywords: Security
Target Release: ---   
Hardware: All   
OS: Linux   
Whiteboard:
Fixed In Version: Doc Type: ---
Doc Text:
A flaw was found in dovecot. The comparison mechanism for `doveadm` passwords and API keys is not fully timing safe. A remote attacker, with network access to the `doveadm` service, could repeatedly make requests and accurately measure response timings. This could allow the attacker to learn the length of the configured secret, which reduces the effort needed to guess the secret value. The secret value itself is not directly disclosed by this vulnerability.
 Story Points: ---
Clone Of: Environment:
Last Closed: Type: ---
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Embargoed:
Bug Depends On: 2526687    
Bug Blocks:    

Description OSIDB Bzimport 2026-08-28 11:23:20 UTC 
The comparison used for the doveadm password and API key is not fully timing safe and can reveal the length of the configured secret. An attacker with access to the same network as the doveadm service, able to make repeated requests and measure response timing accurately, can learn the length of the secret, which reduces the effort needed to guess it. The secret value itself is not disclosed. Restrict network access to the doveadm service to trusted clients. Update to non-vulnerable version. No publicly available exploits are known.