High severity · published Oct 12, 2026
CVE-2026-84319
Nginx UI: MCP configuration tools bypass restricted directive validation and allow secondary authenticated users to execute NJS in Nginx worker context
8.3
CVSS
0.3%
EPSS
No
On KEV
Description
Nginx UI is a web user interface for the Nginx web server. Prior to 2.4.1, the regular HTTP configuration API rejects restricted Nginx directives such as load_module, js_import, and js_content. However, the MCP configuration interface allows a secondary authenticated user to write and apply equivalent restricted configuration content. This allows the user to load ngx_http_js_module.so, import attacker-controlled JavaScript, reload Nginx, and execute NJS in the Nginx worker context. This issue is fixed in version 2.4.1.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:H/A:H
Attack vector
Network
Complexity
Low
Privileges
Low
User interaction
None
Confidentiality
Low
Integrity
High
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.3% · higher than 20% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
NG
nginx-ui · 0xJacky
< 2.4.1 · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-84319
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-84319
x_refsource_CONFIRM
https://github.com/0xJacky/nginx-ui/security/advisories/GHSA-5r62-gj48-897x
x_refsource_MISC
https://github.com/0xJacky/nginx-ui/commit/23d1934099b05b2a01589b48129dc3d3159d91c2
x_refsource_MISC
https://github.com/0xJacky/nginx-ui/releases/tag/v2.4.1
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