CVE-2026-27651
Publication date 24 March 2026
Last updated 27 April 2026
Ubuntu priority
Description
When the ngx_mail_auth_http_module module is enabled on NGINX Plus or NGINX Open Source, undisclosed requests can cause worker processes to terminate. This issue may occur when (1) CRAM-MD5 or APOP authentication is enabled, and (2) the authentication server permits retry by returning the Auth-Wait response header. Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.
Status
| Package | Ubuntu Release | Status |
|---|---|---|
| nginx | 26.04 LTS resolute |
Not affected
|
| 25.10 questing |
Fixed 1.28.0-6ubuntu1.2
|
|
| 24.04 LTS noble |
Fixed 1.24.0-2ubuntu7.7
|
|
| 22.04 LTS jammy |
Fixed 1.18.0-6ubuntu14.10
|
|
| 20.04 LTS focal |
Needs evaluation
|
|
| 18.04 LTS bionic |
Needs evaluation
|
|
| 16.04 LTS xenial |
Needs evaluation
|
|
| 14.04 LTS trusty |
Needs evaluation
|
Severity score breakdown
| Parameter | Value |
|---|---|
| Base score |
7.5 · High
|
| Attack vector | Network |
| Attack complexity | Low |
| Privileges required | None |
| User interaction | None |
| Scope | Unchanged |
| Confidentiality | None |
| Integrity impact | None |
| Availability impact | High |
| Vector | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |