NULL pointer dereference in F5 nginx JavaScript
CVE-2026-78222
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.
CVSS v3 metric
CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.
Affected products
Weakness classification (CWE)
References
- f5sirt@f5.com (vendor-advisory)
Frequently asked questions
- What is CVE-2026-78222?
- CVE-2026-78222 is a high-severity vulnerability in F5 nginx JavaScript, classified under NULL Pointer Dereference. CVSS score: 7.5/10. Published 2026-09-02.
- How severe is CVE-2026-78222?
- High severity. CVSS v3 base score is 7.5 out of 10.