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

CVE-2026-42393 is fixed in 3 products on 1 platform, first by SUSE-SU-2026:23595-1, released September 1, 2026. It is not reported as exploited. Patch Radar priority: Routine.

- Web page: https://patchblox.com/security/cve/CVE-2026-42393
- Priority: Routine
- CVSS: 3.1 (low)
- EPSS: 0.0017
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Aug 28, 2026

## 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.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | dovecot Debian 12.15 (bookworm) | 1:2.3.19.1+dfsg1-2.1+deb12u7 | [DEBIAN-CVE-2026-42393](https://patchblox.com/security/data/fix/linux/debian-cve-2026-42393.md) | Sep 10, 2026 |
| Linux | dovecot Debian 13.5 (trixie) | 1:2.4.1+dfsg1-6+deb13u7 | [DEBIAN-CVE-2026-42393](https://patchblox.com/security/data/fix/linux/debian-cve-2026-42393.md) | Sep 10, 2026 |
| Linux | dovecot Debian 14 | 1:2.4.5+dfsg1-1 | [DEBIAN-CVE-2026-42393](https://patchblox.com/security/data/fix/linux/debian-cve-2026-42393.md) | Sep 10, 2026 |
| Linux | dovecot23 sles 15.6 | 2.3.21.1-150200.76.1 | [SUSE-SU-2026:4139-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-4139-1.md) | Sep 14, 2026 |
| Linux | dovecot23 sles 15.7 | 2.3.21.1-150200.76.1 | [SUSE-SU-2026:4139-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-4139-1.md) | Sep 14, 2026 |
| Linux | dovecot24 opensuse-leap 16.0 | 2.4.4-160000.2.1 | [OPENSUSE-SU-2026:21720-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-21720-1.md) | Sep 1, 2026 |
| Linux | dovecot24 sles 16.0 | 2.4.4-160000.2.1 | [SUSE-SU-2026:23595-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-23595-1.md) | Sep 1, 2026 |

---

Data as of 2026-11-08T06:59:42Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

Free to use with attribution: show "Data: Patchblox Patch Radar" with a link to https://patchblox.com/security/patch-radar. Terms, including what needs a written agreement: https://patchblox.com/security/patch-radar/use-the-data

Product names, logos and trademarks shown on Patch Radar belong to their respective owners. They are used only to identify the software each security fix applies to and to help readers find their platform. Their use does not imply any affiliation with, or endorsement by, those owners, and Patchblox is not affiliated with any of them.