Vulnerability · Published Sep 2, 2026 · Assigned by f5

CVE-2026-78222NGINX ngx_http_js_module vulnerability

High 7.5

In plain English

A high-severity null pointer dereference in NGINX JavaScript from F5. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.6% (higher than 50% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)7.5High

Exploit odds (30 days)0.6%top 49.9% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official description

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 packages & fixed versions

Ecosystem	Package	Fixed in	Advisory
Debian:12	libnginx-mod-js	no fix listed	DEBIAN-CVE-2026-78222
Debian:13	libnginx-mod-js	no fix listed	DEBIAN-CVE-2026-78222
Debian:14	libnginx-mod-js	1.0.1-1	DEBIAN-CVE-2026-78222
Ubuntu:24.04:LTS	libnginx-mod-js	no fix listed	UBUNTU-CVE-2026-78222
Ubuntu:26.10	libnginx-mod-js	no fix listed	UBUNTU-CVE-2026-78222

Affected products (as reported)

Vendor	Product	Versions
F5	NGINX JavaScript	0.5.1 – before 1.0.1

Weakness: CWE-476 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

References

https://my.f5.com/manage/s/article/K000162603 vendor-advisory