CVE-2026-42007An 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 buff…
Updated under an hour ago ()
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It affects Open-Xchange GmbH OX Dovecot Pro and 1 other product. Add what you run to find out whether that includes you.
No exploitation reported and no EPSS estimate yet.
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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.
- CVSS
- 9.1 CRITICAL (v3.1, CNA)CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:H
- Weakness (CWE)
- CWE-416
- Known exploited
- Not in CISA's KEV catalog
- EPSS (exploitation in the next 30 days)
- Not loaded for this CVE
- Assigned by
- OX
- NVD analysis
- Deferred
- Record last updated
- Aug 28, 2026
- First seen by InfoSec Signals
- Oct 9, 2026
Affected products
Open-Xchange GmbH OX Dovecot Pro open_xchange:ox_dovecot_pro (from the name) | from 2.3.0 before 2.3.22.2; from 3.0.0 before 3.0.7; from 3.1.0 before 3.1.6 | CNA record |
Open-Xchange GmbH OX Dovecot CE open_xchange:ox_dovecot_ce (from the name) | from 2.3.0 before 2.4.5 | CNA record |
References
- https://documentation.open-xchange.com/dovecot/security/advisories/csaf/2026/oxdc-adv-2026-0003.jsonvendor-advisory
The CVE record on cve.org NVD's entry
The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.