CVE-2026-27860
5.3
MEDIUM
CVSS 3.1
EPSS 0.04%
Description
If auth_username_chars is empty, it is possible to inject arbitrary LDAP filter to Dovecot's LDAP authentication. This leads to potentially bypassing restrictions and allows probing of LDAP structure. Do not clear out auth_username_chars, or install fixed version. No publicly available exploits are known.
How to fix CVE-2026-27860
To remediate CVE-2026-27860, upgrade the affected package to a fixed version below.
- Alpine/dovecot—upgrade to 2.4.3-r0 or later
- —upgrade to 1:2.4.1+dfsg1-6+deb13u4 or later
Is CVE-2026-27860 being exploited?
Low — EPSS is 0.0%, meaning exploitation activity has not been observed at scale.
Affected packages (2)
- from 0, < 2.4.3-r0
- from 0, < 1:2.4.1+dfsg1-6+deb13u4
CVSS scores
| Source | Version | Severity | Vector |
|---|---|---|---|
| osv | CVSS 3.1 | MEDIUM5.3 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N |