CVE-2026-40016 (GCVE-0-2026-40016)

Vulnerability from cvelistv5 – Published: 2026-05-12 13:28 – Updated: 2026-05-12 15:38
VLAI?
Summary
Attacker can upload a malicious Sieve script over ManageSieve service (or locally) to bypass configured CPU time limits for Sieve up to 130 times of the configured limit. Attacker can use this to degrade server performance and bypass configured CPU time limits for Sieve scripts. Install fixed version, or alternatively prevent direct access to Sieve scripts via ManageSieve or local access. No publicly available exploits are known.
Severity ?
5.3 (Medium)
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H
CWE
  • CWE-400 - Uncontrolled Resource Consumption
Assigner
OX
References
Impacted products
Vendor Product Version
Open-Xchange GmbH OX Dovecot Pro Affected: 0 , ≤ 2.3.0 (semver)
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                "id": "CVE-2026-40016",
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  • Confirmed: The vulnerability has been validated from an analyst's perspective.
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  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.



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