CVE-2026-40016
Undergoing Analysis Undergoing Analysis - In Progress

BaseFortify

Vulnerability report for CVE-2026-40016, including description, CVSS score, EPSS score, affected products, exploitability, helpful resources, and attack-flow context.

Publication date: 2026-05-12

Last updated on: 2026-05-18

Assigner: Open-Xchange

Description

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.

CVSS Scores

EPSS Scores

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Meta Information

Published
2026-05-12
Last Modified
2026-05-18
Generated
2026-06-30
EPSS Evaluated
2026-06-28
NVD

Affected Vendors & Products

Showing 2 associated CPEs
Vendor Product Version / Range
dovecot dovecot to 2.4.4 (exc)
open-xchange dovecot to 3.1.5 (exc)

Helpful Resources

Exploitability

CWE
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KEV
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CWE ID Description
CWE-400 The product does not properly control the allocation and maintenance of a limited resource.

Attack-Flow Graph

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EPSS Chart