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TI-2026-29007 Aliases CVE-2026-40193GHSA-5835-4gvc-32pc

Maddy Mail Server: LDAP Filter Injection via Unsanitized Username

Priority HIGH 75CWE-90Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Impact type
—
Confidentiality · integrity · availability
High · Low · None
Fix status
Fixed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA and GitHub.

Summary

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.

Why it matters now

Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.00419 36th percentileScored 2026-11-07
Public exploit Yes 1 exploit referenceTagged by NVD
Fix Fixed maddy (foxcpp): 0.9.3github.com/foxcpp/maddy (Go): 0.9.3

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
Poc
Automatable
Yes
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
foxcppmaddybefore 0.9.30.9.3Patch availableCNA
—github.com/foxcpp/maddy (Go)before 0.9.30.9.3Patch availableGHSA-5835-4gvc-32pc
  • maddy Vendorfoxcpp Affected before 0.9.3 Fixed in 0.9.3 Patch available CNA
  • github.com/foxcpp/maddy (Go) Vendor— Affected before 0.9.3 Fixed in 0.9.3 Patch available GHSA-5835-4gvc-32pc

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:maddy_project:maddy:*:*:*:*:*:*:*:*before 0.9.3VulnerableMaddy Project
  • cpe:2.3:a:maddy_project:maddy:*:*:*:*:*:*:*:* Versions before 0.9.3 Vulnerable ·Maddy Project

Remediation

  • Fix · CNA maddy (foxcpp) Fixed in 0.9.3
  • Fix · GHSA-5835-4gvc-32pc github.com/foxcpp/maddy (Go) Fixed in 0.9.3 Advisory →

Vendor assessments

Red Hat

Red Hat's page for this CVE →

Not affected: 1 product
  • Red Hat

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-40193
  2. 2026-10-03 Alias added: GHSA-5835-4gvc-32pc

References

Exploit 1

Patch 1

Advisory 1

Other 2

  • TI-2023-12292 Full authentication bypass if SASL authorization username is specified CVSS 3.1CRITICAL 9.8
  • TI-2022-08546 Maddy Mail Server does not implement account expiry CVSS 3.1HIGH 8.8
  • TI-2021-18860 A Broken or Risky Cryptographic Algorithm exists in Max Mazurov Maddy before 0.5.2, which… CVSS 3.1HIGH 7.5

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences