CISA ADP Vulnrichment

Answer in brief

CVE-2026-42391 records a Unknown severity vulnerability in CISA ADP Vulnrichment. The current sources do not mark it as known exploited. The current feed maps Open-Xchange GmbH/OX Dovecot CE (generic), Open-Xchange GmbH/OX Dovecot Pro (generic). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Aug 28, 2026Updated Aug 28, 2026Source checked Aug 28, 2026First seen by HOL Aug 28, 2026Material review Aug 28, 2026

Upstream Advisory

Key facts

Risk: Unknown severitySource severity not reported
Exploitation: Not marked as known exploited
Affected software: 2 mapped packages or products
Fix availability: Available

Why this deserves its current priority

A CVSS score is not reported in the current record. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps Open-Xchange GmbH/OX Dovecot CE (generic), Open-Xchange GmbH/OX Dovecot Pro (generic). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
Open-Xchange GmbH/OX Dovecot CEgeneric	>=2.3.0 <2.4.5	2.4.5
Open-Xchange GmbH/OX Dovecot Progeneric	>=2.3.0 <2.3.22.2 \|\| >=3.0.0 <3.0.7 \|\| >=3.1.0 <3.1.6	2.3.22.2, 3.0.7, 3.1.6

Recommended response

Check inventory. Check lockfiles and deployed manifests for Open-Xchange GmbH/OX Dovecot CE, Open-Xchange GmbH/OX Dovecot Pro.
Review the reported fix. Update Open-Xchange GmbH/OX Dovecot CE to 2.4.5; Open-Xchange GmbH/OX Dovecot Pro to 2.3.22.2 if you use the affected versions. Test the change in a non-production environment first.

Evidence timeline and material changes

Published upstream
Aug 28, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Aug 28, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Aug 28, 2026

Sources and claim methodology

Source referencedocumentation.open-xchange.com

Upstream source description

An unauthenticated attacker can send an IMAP ID command with a very large number of parameters before logging in, which causes memory and CPU usage to grow disproportionately. The login process can be terminated by the out-of-memory handling, which also terminates all other connections handled by the same process. This can cause degradation or denial of service for IMAP logins. Limit the number of connections handled by a single imap-login process. This has a performance impact though. Update to non-vulnerable version. No publicly available exploits are known.

Quoted source text, attributed separately from HOL analysis.