CVE-2026-40013An attacker that has valid credentials can submit a Sieve script containing an extreme numeric literal, which causes an out-of-bounds write when the ManageSieve service compiles the script.
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 submit a Sieve script containing an extreme numeric literal, which causes an out-of-bounds write when the ManageSieve service compiles the script. This causes memory corruption and an observed crash of the ManageSieve process, resulting in denial of service for script management. This might be able to be used for remote code execution. Disable the ManageSieve service if users do not need remote Sieve script management. Update to non-vulnerable version. No publicly available exploits are known.
- CVSS
- 4.3 MEDIUM (v3.1, CNA)CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L
- Weakness (CWE)
- CWE-124
- 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.