# CVE-2026-42395: dovecot: A host listed as a trusted proxy can send forwarding information containing a NUL byte, which crashes the login proce...

CVE-2026-42395 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-2026-42395
- Priority: Routine
- CVSS: 4.3 (medium)
- EPSS: 0.0035
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Aug 28, 2026

## Description

A host listed as a trusted proxy can send forwarding information containing a NUL byte, which crashes the login process on the following login attempt. The login process is terminated, which can cause degradation or denial of service for logins. Deployments that do not configure trusted proxies are not affected. Restrict the list of trusted proxy networks to hosts that are fully under your control. 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-2026-42395](https://patchblox.com/security/data/fix/linux/debian-cve-2026-42395.md) | Sep 10, 2026 |
| Linux | dovecot Debian 13.5 (trixie) | 1:2.4.1+dfsg1-6+deb13u7 | [DEBIAN-CVE-2026-42395](https://patchblox.com/security/data/fix/linux/debian-cve-2026-42395.md) | Sep 10, 2026 |
| Linux | dovecot Debian 14 | 1:2.4.5+dfsg1-1 | [DEBIAN-CVE-2026-42395](https://patchblox.com/security/data/fix/linux/debian-cve-2026-42395.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 |

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Data as of 2026-11-08T13:06:02Z 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

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