CVE-2026-42393
Description
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.
Mitigation
To mitigate this issue, restrict network access to the `doveadm` service to only trusted clients. This can be achieved by configuring firewall rules to limit inbound connections to the `doveadm` service's port from known, secure IP addresses or subnets. Consult your system's firewall documentation (e.g., `firewalld` or `iptables`) for specific configuration steps.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
The following CVSS metrics and score provided are preliminary and subject to review.
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 3.1 | N/A | 3.1 |
| Attack Vector | Adjacent Network | N/A | Adjacent Network |
| Attack Complexity | High | N/A | High |
| Privileges Required | None | N/A | None |
| User Interaction | None | N/A | None |
| Scope | Unchanged | N/A | Unchanged |
| Confidentiality | Low | N/A | Low |
| Integrity Impact | None | N/A | None |
| Availability Impact | None | N/A | None |
Vector
Red Hat: CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N
cve.org: CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N
Understanding the Weakness (CWE)
Confidentiality,Access Control
Technical Impact: Read Application Data; Bypass Protection Mechanism
Frequently Asked Questions
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