CVE-2026-42007
published 2026-08-28CVE-2026-42007: 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…
PriorityP355critical9.1CVSS 3.1
AVNACLPRLUINSCCLILAH
EPSS
0.34%
26.8th percentile
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.
Affected
5 ranges
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| dovecot | dovecot | — | — |
| open-xchange_gmbh | ox_dovecot_ce | >= 2.3.0 < 2.4.5 | 2.4.5 |
| open-xchange_gmbh | ox_dovecot_pro | >= 2.3.0 < 2.3.22.2 | 2.3.22.2 |
| open-xchange_gmbh | ox_dovecot_pro | >= 3.0.0 < 3.0.7 | 3.0.7 |
| open-xchange_gmbh | ox_dovecot_pro | >= 3.1.0 < 3.1.6 | 3.1.6 |
CVSS provenance
nvdv3.19.1CRITICALCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:H
vendor_redhat9.1CRITICAL
Stop checking back — get the weekly exploitation signal.
Every Monday: what got weaponized or added to CISA KEV in the last seven days — each CVE cross-linked to its PoC, Nuclei template, and detection rule. Free, one email a week, unsubscribe in one click.
GHSA
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 buffe
ghsa_unreviewed·2026-08-28
CVE-2026-42007 [CRITICAL] CWE-416 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 buffe
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.
Red Hat
dovecot: Dovecot: Arbitrary Code Execution via Sieve editheader use-after-free
vendor_redhat·2026-08-28·CVSS 9.1
CVE-2026-42007 [CRITICAL] CWE-825 dovecot: Dovecot: Arbitrary Code Execution via Sieve editheader use-after-free
dovecot: Dovecot: Arbitrary Code Execution via Sieve editheader use-after-free
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.
A flaw was found in Dovecot. An authenticated attacker can use a Sieve script with the `editheader` extension to trigger a use-after-free vulnerability in the mail editing code. T
No detection rules found.
No public exploits indexed.
Bugzilla
CVE-2026-42007 dovecot: Dovecot: Arbitrary Code Execution via Sieve editheader use-after-free [fedora-all]
bugzilla·2026-09-01·CVSS 9.1
CVE-2026-42007 [CRITICAL] CVE-2026-42007 dovecot: Dovecot: Arbitrary Code Execution via Sieve editheader use-after-free [fedora-all]
CVE-2026-42007 dovecot: Dovecot: Arbitrary Code Execution via Sieve editheader use-after-free [fedora-all]
Disclaimer: Community trackers are created by Red Hat Product Security team on a best effort basis. Package maintainers are required to ascertain if the flaw indeed affects their package, before starting the update process.
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. Upd
Bugzilla
CVE-2026-42007 dovecot: Dovecot: Arbitrary Code Execution via Sieve editheader use-after-free
bugzilla·2026-08-28·CVSS 9.1
CVE-2026-42007 [CRITICAL] CVE-2026-42007 dovecot: Dovecot: Arbitrary Code Execution via Sieve editheader use-after-free
CVE-2026-42007 dovecot: Dovecot: Arbitrary Code Execution via Sieve editheader use-after-free
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.
2026-08-28
Published