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At a glance
- Nginx disclosed CVE-2026-56434, a use-after-free vulnerability in ngx_http_ssi_module.
- Versions 0.8.11–1.31.2 are affected; Nginx rates the severity as medium.
- Check the version with nginx -V and upgrade to 1.30.4+ or 1.31.3+.
Nginx discloses CVE-2026-56434 in ngx_http_ssi_module: upgrade affected versions
Nginx disclosed CVE-2026-56434, a use-after-free vulnerability in ngx_http_ssi_module affecting versions 0.8.11–1.31.2. Check the installed version with nginx -V and upgrade to 1.30.4+ or 1.31.3+, which are confirmed unaffected branches.
In this article
Nginx has published an advisory for CVE-2026-56434, a use-after-free vulnerability in the module that processes Server Side Includes. See the official Nginx information to confirm the version scope and remediation action.
Overview and technical details
Nginx is a web server and reverse proxy; ngx_http_ssi_module processes Server Side Includes. The vulnerability is identified as a use-after-free and may affect Nginx versions within the affected range.
| Field | Details |
|---|---|
| Product | Nginx |
| Vulnerability ID | CVE-2026-56434 |
| Module | ngx_http_ssi_module |
| Severity | Medium |
| Source | Nginx Security |
Affected systems
| Product | Affected versions | Unaffected versions |
|---|---|---|
| Nginx | 0.8.11–1.31.2 | 1.30.4+ or 1.31.3+ |
Mechanism and impact
CVE-2026-56434 is a use-after-free vulnerability in ngx_http_ssi_module. The information provided states that it may affect Nginx versions in the range listed above.
System checks
Check the installed Nginx version using the following command. Versions 0.8.11–1.31.2 need upgrading; 1.30.4+ or 1.31.3+ are confirmed unaffected.
nginx -V
Remediation and mitigation
Upgrade affected Nginx versions to 1.30.4+ or 1.31.3+, which are confirmed unaffected branches.
Related articles
Nginx: memory disclosure vulnerability CVE-2026-60005 when using the slice module
Nginx has a memory disclosure vulnerability, CVE-2026-60005, when using ngx_http_slice_module. Versions 1.15.8–1.31.2 are affected; check the version and configuration, then upgrade to 1.31.3 or later, or 1.30.4 or later.
