CVE-2026-27859

MEDIUM
5.3
CVSS Score
Published: March 27, 2026 at 08:10 AM UTC
Updated: October 26, 2026 at 12:10 AM UTC
2 products affected across 2 vendorsDovecotOX Dovecot

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Severity
MEDIUM5.3
Exploit prediction
EPSS 0.4%
SSVC
No known exploit

Description

A mail message containing excessive amount of RFC 2231 MIME parameters causes LMTP to use too much CPU. A suitably formatted mail message causes mail delivery process to consume large amounts of CPU time. Use MTA capabilities to limit RFC 2231 MIME parameters in mail messages, or upgrade to fixed version where the processing is limited. No publicly available exploits are known.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v < 2.4.3
v < 3.0.53.1.0 ≤ v < 3.1.4

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

SSVC — Action Prioritization

SSVCNo known exploitAutomatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

5.3MEDIUMOX
Attack Vector
NETWORK
Complexity
LOW
Privileges
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
LOW
Vector?

Quick Info

StatusANALYZED
CWE
CWE-400

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