Answer in brief
CVE-2026-33263 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.
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.
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.
| 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 |
Published upstream
Aug 28, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Aug 28, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Aug 28, 2026
When mail_max_userip_connections is set (default 10) and reached, submission-login can crash with epoll() panic caused by file descriptor handling issues. If running in high-security mode (default for community releases), only the new submission connection gets terminated. If running in high-performance mode (default for Pro releases), all connections handled by the submission-login process will be terminated. The crashes can cause failure for user to send a message, or it can cause duplicate messages to be sent. If TLS is not used (in the backend server processing the submission), duplicate deliveries cannot happen, because the crash can only happen at AUTH stage. Limit the number of connections handled by single submission-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.