Vulnerability Description
maddy is a composable, all-in-one mail server. Versions prior to 0.9.3 contain an LDAP injection vulnerability in the auth.ldap module where user-supplied usernames are interpolated into LDAP search filters and DN strings via strings.ReplaceAll() without any LDAP filter escaping, despite the go-ldap/ldap/v3 library's ldap.EscapeFilter() function being available in the same import. This affects three code paths: the Lookup() filter, the AuthPlain() DN template, and the AuthPlain() filter. An attacker with network access to the SMTP submission or IMAP interface can inject arbitrary LDAP filter expressions through the username field in AUTH PLAIN or LOGIN commands. This enables identity spoofing by manipulating filter results to authenticate as another user, LDAP directory enumeration via wildcard filters, and blind extraction of LDAP attribute values using authentication responses as a boolean oracle or via timing side-channels between the two distinct failure paths. This issue has been fixed in version 0.9.3.
CVSS Score
HIGH
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Maddy Project | Maddy | < 0.9.3 |
Related Weaknesses (CWE)
References
- https://github.com/foxcpp/maddy/commit/6a06337eb41fa87a35697366bcb71c3c962c44baPatch
- https://github.com/foxcpp/maddy/releases/tag/v0.9.3ProductRelease Notes
- https://github.com/foxcpp/maddy/security/advisories/GHSA-5835-4gvc-32pcExploitVendor Advisory
FAQ
What is CVE-2026-40193?
CVE-2026-40193 is a vulnerability with a CVSS score of 8.2 (HIGH). maddy is a composable, all-in-one mail server. Versions prior to 0.9.3 contain an LDAP injection vulnerability in the auth.ldap module where user-supplied usernames are interpolated into LDAP search f...
How severe is CVE-2026-40193?
CVE-2026-40193 has been rated HIGH with a CVSS base score of 8.2/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-40193?
Check the references section above for vendor advisories and patch information. Affected products include: Maddy Project Maddy.