CVE-2026-78222: F5 Nginx JavaScript

High severity, CVSS 7.5. EPSS: 0.6% chance of exploitation in the next 30 days.

A vulnerability exists in NGINX JavaScript where a malformed HTTP response received by ngx.fetch() can crash an NGINX worker when trusted JavaScript reads Response.statusText. Exploitation requires control or influence over the fetched HTTP response. Impact: This vulnerability may allow remote attackers to cause a denial-of-service (DoS) on the NGINX system. There is no control plane exposure; this is a data plane issue only. Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.

Affected products

• F5 Nginx JavaScript: from 0.5.1, before 1.0.1 (fixed in 1.0.1)

Published 2026-09-02. Last modified 2026-09-02.