CVE-2026-40193: maddy is a composable, all-in-one mail server

Q: How do I fix CVE-2026-40193?

maddy: upgrade to 0.9.3. Exact commands for each OS are on this page.

Q: Is CVE-2026-40193 being exploited?

CVE-2026-40193 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2026-40193 affect?

CVE-2026-40193 affects maddy. Severity is high (CVSS 8.2). 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.Replac

Q: How urgent is CVE-2026-40193?

Priority 48/100. High severity; Public exploit reference; Remotely exploitable, no login, no user action

This week

HIGH 8.2REMOTEUPGRADE

CVE-2026-40193 is a high-severity flaw (CVSS 8.2) affecting maddy. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

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(

Why this priority

High severity
Public exploit reference
Remotely exploitable, no login, no user action

A fixed release or distro patch exists.

Risk facts

CVSS score	8.2 (High)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	0.4% (top 64%)
CISA exploited list	No
Weakness	CWE-90
Published	2026-04-16
Last modified	2026-10-26

Publisher (CNA): GitHub, Inc. · Vendor: maddy project

Last updated 2026-10-26 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-04-16 00:16 UTCPublished CVE record published
2026-10-26 21:10 UTCUpdated Record last modified

maddy project maddy UPGRADE

Affected: < 0.9.3

Fixed in: 0.9.3

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy maddy || rpm -q maddy || maddy --version

2. UPGRADE to 0.9.3 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade maddy

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade maddy

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2026-40193?

maddy: upgrade to 0.9.3. Exact commands for each OS are on this page.

Is CVE-2026-40193 being exploited?

CVE-2026-40193 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2026-40193 affect?

CVE-2026-40193 affects maddy. Severity is high (CVSS 8.2). 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.Replac

How urgent is CVE-2026-40193?

Priority 48/100. High severity; Public exploit reference; Remotely exploitable, no login, no user action

References

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