NULL Pointer Dereference Affecting nginx package, versions [0.5.13,1.28.3)[1.29.0,1.29.7)
Threat Intelligence
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
Do your applications use this vulnerable package?
In a few clicks we can analyze your entire application and see what components are vulnerable in your application, and suggest you quick fixes.
Test your applicationsSnyk Learn
Learn about NULL Pointer Dereference vulnerabilities in an interactive lesson.
Start learning- Snyk IDSNYK-UNMANAGED-NGINX-15807034
- published29 Mar 2026
- disclosed24 Mar 2026
- creditArkadi Vainbrand
Introduced: 24 Mar 2026
CVE-2026-27651 (opens in a new tab)How to fix?
Upgrade nginx to version 1.28.3, 1.29.7 or higher.
Overview
Affected versions of this package are vulnerable to NULL Pointer Dereference in the ngx_mail_auth_http_module process when CRAM-MD5 or APOP authentication is enabled and the authentication server allows retry by returning the Auth-Wait response header. An attacker can cause worker processes to terminate by sending specially crafted requests. This is only exploitable if both CRAM-MD5 or APOP authentication is enabled and the authentication server returns the Auth-Wait response header.