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At a glance
- Nginx disclosed CVE-2026-42533, a buffer overflow related to map and regex.
- The affected version range is listed as 0.9.6–1.31.2.
- Check the version and upgrade to 1.31.3+ or 1.30.4+.
Nginx warns of CVE-2026-42533: check map and regex configuration and upgrade
Nginx disclosed CVE-2026-42533, a buffer overflow related to the use of map and regex. Versions 0.9.6–1.31.2 are listed as affected; check your version and upgrade to 1.31.3+ or 1.30.4+.
In this article
Nginx has published an advisory for CVE-2026-42533, a buffer overflow related to the use of map and regex. Refer to the official Nginx advisory for details.
Overview and technical details
Nginx is a web server and reverse proxy used to serve web content and forward traffic. The advisory describes a buffer overflow when using map and regex; the severity is stated as major.
| Field | Details |
|---|---|
| Product | Nginx |
| CVE | CVE-2026-42533 |
| Severity | major |
| Source | Nginx Security |
Affected systems
Nginx versions 0.9.6–1.31.2 are listed as affected. Versions 1.31.3+ and 1.30.4+ are listed as unaffected.
| Product | Affected versions | Unaffected versions |
|---|---|---|
| Nginx | 0.9.6–1.31.2 | 1.31.3+ or 1.30.4+ |
Remediation and mitigation
Check the installed Nginx version using the provided command:
nginx -vCompare the result: versions 1.31.3+ or 1.30.4+ belong to branches listed as unaffected; versions in the 0.9.6–1.31.2 range should be assessed and upgraded.
Upgrade Nginx to a corresponding unaffected version: 1.31.3+ or 1.30.4+.
Related articles
Nginx discloses CVE-2026-93479: check versions and upgrade affected branches
Nginx disclosed buffer overflow CVE-2026-93479 during script evaluation, rated medium severity. Nginx 1.31.2–1.31.6 and 1.30.0–1.30.5 are affected; check the installed version and upgrade to 1.31.7+ or 1.30.6+, respectively.