CVE-2026-27851: Open-Xchange OX Dovecot Pro · Improper Handling of Extra Parameters
Affects Open-Xchange OX Dovecot ProSource CVE Database V5
Not known to be exploited · CVSS 7.4 High.
Data as of 30 Oct 2026, 11:52 UTC
- EPSS
- 0.4% chance of exploitation in 30 days – higher than 34% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:NExploitation evidence
Disclosed: evidence found.
CVE published 12 May 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 30 Oct 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| Open-Xchange GmbHOX Dovecot Pro | Affected
| Fixed in– |
AI-suggested
The vendor advisory and Red Hat advisory do not indicate any temporary or official remediation. Users should avoid using the safe filter with variable expansion in affected versions until a fixed version is released.
Description
When safe filter is used with variable expansion, all following pipelines on the same string are incorrectly interpreted as safe too, enabling unsafe data to be unescaped. This can enable SQL / LDAP injection attacks when used in authentication. Avoid using safe filter until on fixed version. No publicly available exploits are known.
References
- documentation.open-xchange.com/dovecot/security/advisories/csaf/2026/oxdc-adv-2026-0002.json (opens in a new tab)
- access.redhat.com/security/cve/CVE-2026-27851 (opens in a new tab)
- bugzilla.redhat.com/show_bug.cgi?id=2476471 (opens in a new tab)
- security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-27851.json (opens in a new tab)