High 8.8Published Oct 12, 2026

CVE-2026-84317Nginx UI: MCP nginx_config_add skips config directive validation → authenticated nginx directive injection (RCE on the official image)

Updated under an hour ago (2026-10-19 10:00 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 0.38%, higher than 30% 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. Prior to 2.4.1, internal/config/validation.go (ValidateConfigFile) is a security control that blocks dangerous nginx directives — js_*, perl_*, load_module of the njs/perl modules, and user root. It is enforced on three of the four config-write paths: api/config/add.go, api/config/modify.go, and mcp/config/config_modify.go. The fourth path — the MCP tool nginx_config_add (mcp/config/config_add.go) — does NOT call it: it writes the caller-supplied content straight to disk and reloads nginx. An authenticated MCP caller (or an MCP agent induced via prompt injection) can therefore inject exactly the directives the control is meant to block, leading to nginx code execution on deployments where the njs/perl module is available (e.g. the official Docker image). 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-20, CWE-693
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): 0.38% (percentile 30)
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)	before 2.4.1	CNA record

References

https://github.com/0xJacky/nginx-ui/security/advisories/GHSA-76pm-mq2q-9gcrx-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.