Vulnerability · Published Sep 2, 2026 · Assigned by f5
CVE-2026-18329NGINX ngx_http_js_module vulnerability
High 8.2
In plain English
A high-severity security flaw 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 51% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
Description NGINX JavaScript (njs) and QuickJS (qjs) engines have a vulnerability when a js_access handler performs asynchronous request body processing and an exception is thrown during asynchronous access-control evaluation before an explicit access denial is returned. An unauthenticated attacker can exploit this vulnerability by sending a crafted HTTP request that triggers an error condition in the access validation logic. This may cause the js_access phase to fail open, allowing the request to proceed instead of being denied, resulting in an authentication or authorization bypass and unauthorized access to protected resources. Impact This vulnerability may allow remote attackers to bypass js_access controls. 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:14 | libnginx-mod-js | 1.0.1-1 | DEBIAN-CVE-2026-18329 |
| Ubuntu:24.04:LTS | libnginx-mod-js | no fix listed | UBUNTU-CVE-2026-18329 |
| Ubuntu:26.10 | libnginx-mod-js | no fix listed | UBUNTU-CVE-2026-18329 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| F5 | NGINX JavaScript | 1.0.0 – before 1.0.10.9.9 – before * |
Weakness: CWE-636 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N
References
- https://my.f5.com/manage/s/article/K000162599 vendor-advisory