CVE-2023-27582
Full authentication bypass if SASL authorization username is specified
maddy is a composable, all-in-one mail server. Starting with version 0.2.0 and prior to version 0.6.3, maddy allows a full authentication bypass if SASL authorization username is specified when using the PLAIN authentication mechanisms. Instead of validating the specified username, it is accepted as is after checking the credentials for the authentication username. maddy 0.6.3 includes the fix for the bug. There are no known workarounds.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- High
- Integrity
- High
- Availability
- None
Exploit likelihood
What each source reports
CVE List Score used
Full authentication bypass if SASL authorization username is specified
maddy is a composable, all-in-one mail server. Starting with version 0.2.0 and prior to version 0.6.3, maddy allows a full authentication bypass if SASL authorization username is specified when using the PLAIN authentication mechanisms. Instead of validating the specified username, it is accepted as is after checking the credentials for the authentication username. maddy 0.6.3 includes the fix for the bug. There are no known workarounds.
- Record
CVE-2023-27582- CVSS 3.1
- 9.1 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N - Weakness
- CWE-287, CWE-305
- Updated
- 2026-11-02
EUVDEUVD-2023-0863
maddy is a composable, all-in-one mail server. Starting with version 0.2.0 and prior to version 0.6.3, maddy allows a full authentication bypass if SASL authorization username is specified when using the PLAIN authentication mechanisms. Instead of validating the specified username, it is accepted as is after checking the credentials for the authentication username. maddy 0.6.3 includes the fix for the bug. There are no known workarounds.
- Record
EUVD-2023-0863- CVSS 3.1
- 9.1 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-4g76-w3xw-2x6w
Full authentication bypass if SASL authorization username is specified
Impact
maddy 0.2.0 - 0.6.2 allows a full authentication bypass if SASL authorization username is specified when using the PLAIN authentication mechanisms. Instead of validating the specified authorization username, it is accepted as is after checking the credentials for the authentication username.
Patches
maddy 0.6.3 includes the fix for the bug.
Workarounds
There is no way to fix the issue without upgrading.
References
- Commit that introduced the vulnerable code: https://github.com/foxcpp/maddy/commit/55a91a37b71210f34f98f4d327c30308fe24399a
- Fix: https://github.com/foxcpp/maddy/commit/9f58cb64b39cdc01928ec463bdb198c4c2313a9c
- Record
GHSA-4g76-w3xw-2x6w- CVSS 3.1
- 9.1 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N - Weakness
- CWE-287
- Updated
- 2026-11-02
NVD
maddy is a composable, all-in-one mail server. Starting with version 0.2.0 and prior to version 0.6.3, maddy allows a full authentication bypass if SASL authorization username is specified when using the PLAIN authentication mechanisms. Instead of validating the specified username, it is accepted as is after checking the credentials for the authentication username. maddy 0.6.3 includes the fix for the bug. There are no known workarounds.
- Record
CVE-2023-27582- CVSS 3.1
- 9.1 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N - CVSS 3.1
- 9.8 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - Weakness
- CWE-287, CWE-305
- Updated
- 2026-11-02
OSVALPINE-CVE-2023-27582
maddy is a composable, all-in-one mail server. Starting with version 0.2.0 and prior to version 0.6.3, maddy allows a full authentication bypass if SASL authorization username is specified when using the PLAIN authentication mechanisms. Instead of validating the specified username, it is accepted as is after checking the credentials for the authentication username. maddy 0.6.3 includes the fix for the bug. There are no known workarounds.
- Record
ALPINE-CVE-2023-27582- CVSS 3.1
- 9.8 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - Updated
- 2026-11-03
OSV
Full authentication bypass if SASL authorization username is specified
maddy is a composable, all-in-one mail server. Starting with version 0.2.0 and prior to version 0.6.3, maddy allows a full authentication bypass if SASL authorization username is specified when using the PLAIN authentication mechanisms. Instead of validating the specified username, it is accepted as is after checking the credentials for the authentication username. maddy 0.6.3 includes the fix for the bug. There are no known workarounds.
- Record
CVE-2023-27582- CVSS 3.1
- 9.1 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N - Weakness
- CWE-287, CWE-305
- Updated
- 2026-11-02
OSVGHSA-4g76-w3xw-2x6w
Full authentication bypass if SASL authorization username is specified
Impact
maddy 0.2.0 - 0.6.2 allows a full authentication bypass if SASL authorization username is specified when using the PLAIN authentication mechanisms. Instead of validating the specified authorization username, it is accepted as is after checking the credentials for the authentication username.
Patches
maddy 0.6.3 includes the fix for the bug.
Workarounds
There is no way to fix the issue without upgrading.
References
- Commit that introduced the vulnerable code: https://github.com/foxcpp/maddy/commit/55a91a37b71210f34f98f4d327c30308fe24399a
- Fix: https://github.com/foxcpp/maddy/commit/9f58cb64b39cdc01928ec463bdb198c4c2313a9c
- Record
GHSA-4g76-w3xw-2x6w- CVSS 3.1
- 9.1 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N - Weakness
- CWE-287
- Updated
- 2026-11-02
OSVGO-2023-1630 No score
Full authentication bypass if SASL authorization username is specified in github.com/foxcpp/maddy
Full authentication bypass if SASL authorization username is specified in github.com/foxcpp/maddy
- Record
GO-2023-1630- Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
github.com/foxcpp/maddyGo |
0.2.0 up to 0.6.3 | 0.6.3 |
maddyAlpine:v3.23 |
0.2.0 up to 0.6.3-r0 | 0.6.3-r0 |
maddyAlpine:v3.24 |
0.2.0 up to 0.6.3-r0 | 0.6.3-r0 |
History
| Recorded | Changed | Sources |
|---|---|---|
| affected, aliases, references | OSV | |
| first indexed | CVE List, EUVD, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2023-27582 is a critical vulnerability (CVSS 9.1) in Foxcpp Maddy, published March 13, 2023. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 1.02%, the 63rd percentile. Fixed in github.com/foxcpp/maddy 0.6.3.
References
github.com/foxcpp/maddy/security/advisories/GHSA-4g76-w3xw-2x6w
nvd.nist.gov/vuln/detail/CVE-2023-27582
security.alpinelinux.org/vuln/CVE-2023-27582