18 May 2026
Reference: CVE-2026-42945
1. What is being reported?
The vulnerability affects a part of NGINX that handles URL rewriting. Under certain conditions, an attacker can send specially crafted web requests that cause the server to crash or, in some cases, allow the attacker to take control of the server. This happens without needing to log in or have special access.
2. What this means in plain English
For small organisations, this means your website or online services using NGINX could suddenly stop working or be taken over by attackers if the vulnerability is exploited. This could lead to downtime, loss of customer trust, or exposure of sensitive information.
3. Could this affect a small business?
If your organisation uses NGINX Plus or the open-source NGINX software for your website or online services, you could be affected. If you do not use NGINX or your software is no longer supported, this vulnerability likely does not affect you. Ask your IT provider if you are unsure.
4. What to do now
- Check if your website or services use NGINX software, and identify the version in use.
- Contact your IT provider or software supplier to confirm if your NGINX version is vulnerable.
- Apply any available updates or patches from NGINX to fix this vulnerability as soon as possible.
- Ensure your systems have security features like Address Space Layout Randomization (ASLR) enabled to reduce risk.
5. Ask your IT provider
Can you confirm if our NGINX web server is affected by CVE-2026-42945 and what steps are being taken to protect us?
6. Bottom line
If you use NGINX for your website, act quickly to check and update your software to avoid crashes or security breaches.
Information based on NVD, CISA KEV and reputable security news reporting.