An unauthenticated attacker can crash the ManageSieve login process by sending a small malformed command before authenticating. If running in high-security mode (default for community releases), only the attacker's own connection is terminated. If running in high-performance mode (default for Pro releases), all connections handled by the same managesieve-login process are terminated. Repeating the attack can cause denial of service for Sieve script management. Restrict network access to the ManageSieve service to trusted clients. Update to non-vulnerable version. No publicly available exploits are known.
Advisories

No advisories yet.

Fixes

Solution

No solution given by the vendor.


Workaround

No workaround given by the vendor.

History

Fri, 28 Aug 2026 14:00:00 +0000

Type Values Removed Values Added
Title ManageSieve Service Denial of Service via Malformed Command

Fri, 28 Aug 2026 11:30:00 +0000

Type Values Removed Values Added
Description An unauthenticated attacker can crash the ManageSieve login process by sending a small malformed command before authenticating. If running in high-security mode (default for community releases), only the attacker's own connection is terminated. If running in high-performance mode (default for Pro releases), all connections handled by the same managesieve-login process are terminated. Repeating the attack can cause denial of service for Sieve script management. Restrict network access to the ManageSieve service to trusted clients. Update to non-vulnerable version. No publicly available exploits are known.
Weaknesses CWE-400
References
Metrics cvssV3_1

{'score': 7.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'}


Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: OX

Published:

Updated: 2026-08-28T15:55:19.368Z

Reserved: 2026-03-23T12:58:38.267Z

Link: CVE-2026-33605

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-08-28T12:16:27.740

Modified: 2026-08-28T20:17:25.630

Link: CVE-2026-33605

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-08-28T13:45:17Z

Weaknesses