Answer in brief
CVE-2026-40203 records a Low severity (CVSS 3.7) 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.
CVSS is 3.7. 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
Sep 3, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Aug 28, 2026
When IMAP compression is enabled, the same compression state is reused across responses in a session, so response sizes depend on both attacker-supplied mail and other mail in the same mailbox. An attacker that can send mail to a user and can also observe the sizes of that user's IMAP traffic can confirm whether the body of a small message matches a guessed text. Recovery of arbitrary unknown content was not demonstrated, but the attack can disclose whether a secret-like message body matches a candidate. Disable IMAP compression. Update to non-vulnerable version. No publicly available exploits are known.
Quoted source text, attributed separately from HOL analysis.