# CVE-2026-42007: dovecot: An attacker that has valid credentials can use a Sieve script with the editheader extension to trigger a use-after-fr...

CVE-2026-42007 is fixed in 12 products on 1 platform, first by RHSA-2026:79371, released August 28, 2026. It is not reported as exploited. Patch Radar priority: High.

- Web page: https://patchblox.com/security/cve/CVE-2026-42007
- Priority: High
- CVSS: 9.1 (important)
- EPSS: 0.0035
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Aug 28, 2026

## Description

An attacker that has valid credentials can use a Sieve script with the editheader extension to trigger a use-after-free in the mail editing code, and to write memory contents beyond the intended buffer into the delivered mail. This causes memory leak and opportunity to do memory corruption during mail delivery, which can crash the delivery process and may allow execution of arbitrary code in the context of that process. Disable the Sieve editheader extension. 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-2026-42007](https://patchblox.com/security/data/fix/linux/debian-cve-2026-42007.md) | Sep 10, 2026 |
| Linux | dovecot Debian 13.5 (trixie) | 1:2.4.1+dfsg1-6+deb13u7 | [DEBIAN-CVE-2026-42007](https://patchblox.com/security/data/fix/linux/debian-cve-2026-42007.md) | Sep 10, 2026 |
| Linux | dovecot Debian 14 | 1:2.4.5+dfsg1-1 | [DEBIAN-CVE-2026-42007](https://patchblox.com/security/data/fix/linux/debian-cve-2026-42007.md) | Sep 10, 2026 |
| Linux | dovecot Fedora 43 | 1:2.4.5-1.fc43 | [FEDORA-2026-E8A6485109](https://patchblox.com/security/data/fix/linux/fedora-2026-e8a6485109.md) | Sep 10, 2026 |
| Linux | dovecot RHEL 10 | 2.3.21-19.el10_2.8 | [RHSA-2026:79371](https://patchblox.com/security/data/fix/linux/rhsa-2026-79371.md) | Aug 28, 2026 |
| Linux | dovecot RHEL 8 | 1:2.3.16-16.el8_10 | [RHSA-2026:76763](https://patchblox.com/security/data/fix/linux/rhsa-2026-76763.md) | Oct 6, 2026 |
| Linux | dovecot RHEL 9 | 1:2.3.16-18.el9_8.8 | [RHSA-2026:80825](https://patchblox.com/security/data/fix/linux/rhsa-2026-80825.md) | Oct 13, 2026 |
| Linux | dovecot almalinux 10 | 1:2.3.21-19.el10_2.8 | [ALSA-2026:79371](https://patchblox.com/security/data/fix/linux/alsa-2026-79371.md) | Oct 8, 2026 |
| Linux | dovecot almalinux 8 | 1:2.3.16-16.el8_10 | [ALSA-2026:76763](https://patchblox.com/security/data/fix/linux/alsa-2026-76763.md) | Oct 6, 2026 |
| Linux | dovecot almalinux 9 | 1:2.3.16-18.el9_8.8 | [ALSA-2026:80825](https://patchblox.com/security/data/fix/linux/alsa-2026-80825.md) | Nov 7, 2026 |
| Linux | dovecot amzn 2023 | 1:2.3.20-1.amzn2023.0.4 | [ALAS2023-2026-3109](https://patchblox.com/security/data/fix/linux/alas2023-2026-3109.md) | Sep 28, 2026 |
| Linux | dovecot ol 10 | 1:2.3.21-19.el10_2.8 | [ELSA-2026-79371](https://patchblox.com/security/data/fix/linux/elsa-2026-79371.md) | Oct 8, 2026 |
| Linux | dovecot ol 8 | 1:2.3.16-16.el8_10 | [ELSA-2026-76763](https://patchblox.com/security/data/fix/linux/elsa-2026-76763.md) | Oct 6, 2026 |
| Linux | dovecot ol 9 | 1:2.3.16-18.el9_8.8 | [ELSA-2026-80825](https://patchblox.com/security/data/fix/linux/elsa-2026-80825.md) | Nov 7, 2026 |
| Linux | dovecot rocky 10 | 1:2.3.21-19.el10_2.8 | [RLSA-2026:79371](https://patchblox.com/security/data/fix/linux/rlsa-2026-79371.md) | Nov 7, 2026 |
| Linux | dovecot rocky 8 | 1:2.3.16-16.el8_10 | [RLSA-2026:76763](https://patchblox.com/security/data/fix/linux/rlsa-2026-76763.md) | Oct 7, 2026 |
| Linux | dovecot rocky 9 | 1:2.3.16-18.el9_8.8 | [RLSA-2026:80825](https://patchblox.com/security/data/fix/linux/rlsa-2026-80825.md) | Nov 7, 2026 |
| Linux | dovecot-debuginfo Fedora 43 | 1:2.4.5-1.fc43 | [FEDORA-2026-E8A6485109](https://patchblox.com/security/data/fix/linux/fedora-2026-e8a6485109.md) | Sep 10, 2026 |
| Linux | dovecot-debuginfo amzn 2023 | 1:2.3.20-1.amzn2023.0.4 | [ALAS2023-2026-3109](https://patchblox.com/security/data/fix/linux/alas2023-2026-3109.md) | Sep 28, 2026 |
| Linux | dovecot-debugsource Fedora 43 | 1:2.4.5-1.fc43 | [FEDORA-2026-E8A6485109](https://patchblox.com/security/data/fix/linux/fedora-2026-e8a6485109.md) | Sep 10, 2026 |
| Linux | dovecot-debugsource amzn 2023 | 1:2.3.20-1.amzn2023.0.4 | [ALAS2023-2026-3109](https://patchblox.com/security/data/fix/linux/alas2023-2026-3109.md) | Sep 28, 2026 |
| Linux | dovecot-devel Fedora 43 | 1:2.4.5-1.fc43 | [FEDORA-2026-E8A6485109](https://patchblox.com/security/data/fix/linux/fedora-2026-e8a6485109.md) | Sep 10, 2026 |
| Linux | dovecot-devel RHEL 8 | 1:2.3.16-16.el8_10 | [RHSA-2026:76763](https://patchblox.com/security/data/fix/linux/rhsa-2026-76763.md) | Oct 6, 2026 |
| Linux | dovecot-devel RHEL 9 | 1:2.3.16-18.el9_8.8 | [RHSA-2026:80825](https://patchblox.com/security/data/fix/linux/rhsa-2026-80825.md) | Oct 13, 2026 |
| Linux | dovecot-devel almalinux 10 | 1:2.3.21-19.el10_2.8 | [ALSA-2026:79371](https://patchblox.com/security/data/fix/linux/alsa-2026-79371.md) | Oct 8, 2026 |
| Linux | dovecot-devel almalinux 8 | 1:2.3.16-16.el8_10 | [ALSA-2026:76763](https://patchblox.com/security/data/fix/linux/alsa-2026-76763.md) | Oct 6, 2026 |
| Linux | dovecot-devel almalinux 9 | 1:2.3.16-18.el9_8.8 | [ALSA-2026:80825](https://patchblox.com/security/data/fix/linux/alsa-2026-80825.md) | Nov 7, 2026 |
| Linux | dovecot-devel amzn 2023 | 1:2.3.20-1.amzn2023.0.4 | [ALAS2023-2026-3109](https://patchblox.com/security/data/fix/linux/alas2023-2026-3109.md) | Sep 28, 2026 |
| Linux | dovecot-devel ol 10 | 1:2.3.21-19.el10_2.8 | [ELSA-2026-79371](https://patchblox.com/security/data/fix/linux/elsa-2026-79371.md) | Oct 8, 2026 |
| Linux | dovecot-devel ol 8 | 1:2.3.16-16.el8_10 | [ELSA-2026-76763](https://patchblox.com/security/data/fix/linux/elsa-2026-76763.md) | Oct 6, 2026 |
| Linux | dovecot-devel ol 9 | 1:2.3.16-18.el9_8.8 | [ELSA-2026-80825](https://patchblox.com/security/data/fix/linux/elsa-2026-80825.md) | Nov 7, 2026 |
| Linux | dovecot-mysql Fedora 43 | 1:2.4.5-1.fc43 | [FEDORA-2026-E8A6485109](https://patchblox.com/security/data/fix/linux/fedora-2026-e8a6485109.md) | Sep 10, 2026 |
| Linux | dovecot-mysql RHEL 8 | 1:2.3.16-16.el8_10 | [RHSA-2026:76763](https://patchblox.com/security/data/fix/linux/rhsa-2026-76763.md) | Oct 6, 2026 |
| Linux | dovecot-mysql RHEL 9 | 1:2.3.16-18.el9_8.8 | [RHSA-2026:80825](https://patchblox.com/security/data/fix/linux/rhsa-2026-80825.md) | Oct 13, 2026 |
| Linux | dovecot-mysql almalinux 10 | 1:2.3.21-19.el10_2.8 | [ALSA-2026:79371](https://patchblox.com/security/data/fix/linux/alsa-2026-79371.md) | Oct 8, 2026 |
| Linux | dovecot-mysql almalinux 8 | 1:2.3.16-16.el8_10 | [ALSA-2026:76763](https://patchblox.com/security/data/fix/linux/alsa-2026-76763.md) | Oct 6, 2026 |
| Linux | dovecot-mysql almalinux 9 | 1:2.3.16-18.el9_8.8 | [ALSA-2026:80825](https://patchblox.com/security/data/fix/linux/alsa-2026-80825.md) | Nov 7, 2026 |
| Linux | dovecot-mysql amzn 2023 | 1:2.3.20-1.amzn2023.0.4 | [ALAS2023-2026-3109](https://patchblox.com/security/data/fix/linux/alas2023-2026-3109.md) | Sep 28, 2026 |
| Linux | dovecot-mysql ol 10 | 1:2.3.21-19.el10_2.8 | [ELSA-2026-79371](https://patchblox.com/security/data/fix/linux/elsa-2026-79371.md) | Oct 8, 2026 |
| Linux | dovecot-mysql ol 8 | 1:2.3.16-16.el8_10 | [ELSA-2026-76763](https://patchblox.com/security/data/fix/linux/elsa-2026-76763.md) | Oct 6, 2026 |
| Linux | dovecot-mysql ol 9 | 1:2.3.16-18.el9_8.8 | [ELSA-2026-80825](https://patchblox.com/security/data/fix/linux/elsa-2026-80825.md) | Nov 7, 2026 |
| Linux | dovecot-mysql-debuginfo Fedora 43 | 1:2.4.5-1.fc43 | [FEDORA-2026-E8A6485109](https://patchblox.com/security/data/fix/linux/fedora-2026-e8a6485109.md) | Sep 10, 2026 |
| Linux | dovecot-mysql-debuginfo amzn 2023 | 1:2.3.20-1.amzn2023.0.4 | [ALAS2023-2026-3109](https://patchblox.com/security/data/fix/linux/alas2023-2026-3109.md) | Sep 28, 2026 |
| Linux | dovecot-pgsql Fedora 43 | 1:2.4.5-1.fc43 | [FEDORA-2026-E8A6485109](https://patchblox.com/security/data/fix/linux/fedora-2026-e8a6485109.md) | Sep 10, 2026 |
| Linux | dovecot-pgsql RHEL 8 | 1:2.3.16-16.el8_10 | [RHSA-2026:76763](https://patchblox.com/security/data/fix/linux/rhsa-2026-76763.md) | Oct 6, 2026 |
| Linux | dovecot-pgsql RHEL 9 | 1:2.3.16-18.el9_8.8 | [RHSA-2026:80825](https://patchblox.com/security/data/fix/linux/rhsa-2026-80825.md) | Oct 13, 2026 |
| Linux | dovecot-pgsql almalinux 10 | 1:2.3.21-19.el10_2.8 | [ALSA-2026:79371](https://patchblox.com/security/data/fix/linux/alsa-2026-79371.md) | Oct 8, 2026 |
| Linux | dovecot-pgsql almalinux 8 | 1:2.3.16-16.el8_10 | [ALSA-2026:76763](https://patchblox.com/security/data/fix/linux/alsa-2026-76763.md) | Oct 6, 2026 |
| Linux | dovecot-pgsql almalinux 9 | 1:2.3.16-18.el9_8.8 | [ALSA-2026:80825](https://patchblox.com/security/data/fix/linux/alsa-2026-80825.md) | Nov 7, 2026 |
| Linux | dovecot-pgsql amzn 2023 | 1:2.3.20-1.amzn2023.0.4 | [ALAS2023-2026-3109](https://patchblox.com/security/data/fix/linux/alas2023-2026-3109.md) | Sep 28, 2026 |
| Linux | dovecot-pgsql ol 10 | 1:2.3.21-19.el10_2.8 | [ELSA-2026-79371](https://patchblox.com/security/data/fix/linux/elsa-2026-79371.md) | Oct 8, 2026 |
| Linux | dovecot-pgsql ol 8 | 1:2.3.16-16.el8_10 | [ELSA-2026-76763](https://patchblox.com/security/data/fix/linux/elsa-2026-76763.md) | Oct 6, 2026 |
| Linux | dovecot-pgsql ol 9 | 1:2.3.16-18.el9_8.8 | [ELSA-2026-80825](https://patchblox.com/security/data/fix/linux/elsa-2026-80825.md) | Nov 7, 2026 |
| Linux | dovecot-pgsql-debuginfo Fedora 43 | 1:2.4.5-1.fc43 | [FEDORA-2026-E8A6485109](https://patchblox.com/security/data/fix/linux/fedora-2026-e8a6485109.md) | Sep 10, 2026 |
| Linux | dovecot-pgsql-debuginfo amzn 2023 | 1:2.3.20-1.amzn2023.0.4 | [ALAS2023-2026-3109](https://patchblox.com/security/data/fix/linux/alas2023-2026-3109.md) | Sep 28, 2026 |
| Linux | dovecot-pigeonhole Fedora 43 | 1:2.4.5-1.fc43 | [FEDORA-2026-E8A6485109](https://patchblox.com/security/data/fix/linux/fedora-2026-e8a6485109.md) | Sep 10, 2026 |
| Linux | dovecot-pigeonhole RHEL 8 | 1:2.3.16-16.el8_10 | [RHSA-2026:76763](https://patchblox.com/security/data/fix/linux/rhsa-2026-76763.md) | Oct 6, 2026 |
| Linux | dovecot-pigeonhole RHEL 9 | 1:2.3.16-18.el9_8.8 | [RHSA-2026:80825](https://patchblox.com/security/data/fix/linux/rhsa-2026-80825.md) | Oct 13, 2026 |
| Linux | dovecot-pigeonhole almalinux 10 | 1:2.3.21-19.el10_2.8 | [ALSA-2026:79371](https://patchblox.com/security/data/fix/linux/alsa-2026-79371.md) | Oct 8, 2026 |
| Linux | dovecot-pigeonhole almalinux 8 | 1:2.3.16-16.el8_10 | [ALSA-2026:76763](https://patchblox.com/security/data/fix/linux/alsa-2026-76763.md) | Oct 6, 2026 |
| Linux | dovecot-pigeonhole almalinux 9 | 1:2.3.16-18.el9_8.8 | [ALSA-2026:80825](https://patchblox.com/security/data/fix/linux/alsa-2026-80825.md) | Nov 7, 2026 |
| Linux | dovecot-pigeonhole amzn 2023 | 1:2.3.20-1.amzn2023.0.4 | [ALAS2023-2026-3109](https://patchblox.com/security/data/fix/linux/alas2023-2026-3109.md) | Sep 28, 2026 |
| Linux | dovecot-pigeonhole ol 10 | 1:2.3.21-19.el10_2.8 | [ELSA-2026-79371](https://patchblox.com/security/data/fix/linux/elsa-2026-79371.md) | Oct 8, 2026 |
| Linux | dovecot-pigeonhole ol 8 | 1:2.3.16-16.el8_10 | [ELSA-2026-76763](https://patchblox.com/security/data/fix/linux/elsa-2026-76763.md) | Oct 6, 2026 |
| Linux | dovecot-pigeonhole ol 9 | 1:2.3.16-18.el9_8.8 | [ELSA-2026-80825](https://patchblox.com/security/data/fix/linux/elsa-2026-80825.md) | Nov 7, 2026 |
| Linux | dovecot-pigeonhole-debuginfo Fedora 43 | 1:2.4.5-1.fc43 | [FEDORA-2026-E8A6485109](https://patchblox.com/security/data/fix/linux/fedora-2026-e8a6485109.md) | Sep 10, 2026 |
| Linux | dovecot-pigeonhole-debuginfo amzn 2023 | 1:2.3.20-1.amzn2023.0.4 | [ALAS2023-2026-3109](https://patchblox.com/security/data/fix/linux/alas2023-2026-3109.md) | Sep 28, 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 2026-11-07T18:46:35Z 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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