Critical severity · published May 12, 2026
CVE-2026-27851
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
9.1
CVSS
0.4%
EPSS
No
On KEV
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.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
High
Integrity
High
Availability
None
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.4% · higher than 35% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
OD
OX Dovecot Pro · Open-Xchange GmbH
through 3.1.4; through 2.4.3 · source: vendor
DO
Dovecot · Dovecot
before 2.4.4 · source: NVD
RH
Red Hat Enterprise Linux 6 · Red Hat
All versions, or not specified · source: CISA
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-27851
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-27851
Vendor Advisory
https://documentation.open-xchange.com/dovecot/security/advisories/csaf/2026/oxdc-adv-2026-0002.json
access.redhat.com
https://access.redhat.com/security/cve/CVE-2026-27851
bugzilla.redhat.com
https://bugzilla.redhat.com/show_bug.cgi?id=2476471
security.access.redhat.com
https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-27851.json
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