High 8.8Published Oct 12, 2026

CVE-2026-84318Nginx UI: MCP `nginx_config_add` Bypasses Directive Validation — Authenticated RCE

Updated under an hour ago (2026-10-19 09:50 UTC)

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It affects 0xJacky nginx-ui. Add what you run to find out whether that includes you.

EPSS puts the chance of exploitation in the next 30 days at 0.62%, higher than 48% of scored CVEs.

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Every CVE for 0xJacky nginx-ui

Exploited in the last 30 days

Nginx UI is a web user interface for the Nginx web server. From 2.0.0-rc.6 until 2.4.1, the MCP tool nginx_config_add writes nginx configuration files to disk and triggers an nginx reload without calling config.ValidateConfigFile. The identical flow in the REST API (POST /api/configs) does call that function and correctly rejects dangerous directives. An authenticated attacker can exploit this gap to write config files containing any blocked directive (perl, js_import, load_module, user root, etc.), bypassing nginx-ui's entire security layer. On a server with the nginx Perl, njs, or Lua module loaded, this is post-authentication Remote Code Execution. This issue is fixed in version 2.4.1.

CVSS: 8.8 HIGH (v3.1, CNA)CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Weakness (CWE): CWE-693
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): 0.62% (percentile 48)
Assigned by: GitHub_M
NVD analysis: Deferred
Record last updated: Oct 13, 2026
First seen by InfoSec Signals: Oct 12, 2026

Affected products

Affected products

0xJacky nginx-ui 0xjacky:nginx_ui (from the name)	from 2.0.0-rc.6, < 2.4.1	CNA record

References

https://github.com/0xJacky/nginx-ui/security/advisories/GHSA-9jww-cxg5-rj9mx-refsource-confirm
https://github.com/0xJacky/nginx-ui/commit/23d1934099b05b2a01589b48129dc3d3159d91c2x-refsource-misc
https://github.com/0xJacky/nginx-ui/releases/tag/v2.4.1x-refsource-misc

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.