{"id":"CVE-2026-84317","url":"https://www.cyber-defence.io/tools/cve/CVE-2026-84317","generatedAt":"2026-10-28T03:31:50.799Z","title":"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…","description":"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.","published":"2026-10-12T21:17:22.000Z","lastModified":"2026-10-13T18:17:26.000Z","status":"Deferred","sourceIdentifier":"security-advisories@github.com","cvss":{"version":"3.1","score":8.8,"severity":"HIGH","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H"},"cwe":["CWE-20","CWE-693"],"affected":[],"epss":{"score":0.00478,"percentile":0.40962,"date":"2026-10-26","history":[{"date":"2026-10-13","score":0.00376,"percentile":0.29678}]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"high","text":"High impact if exploited, but EPSS currently rates exploitation as unlikely (0.48%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit."},"changes":[{"kind":"new","label":"New CVE","at":"2026-10-12T21:17:22.000Z","detail":{"score":"8.8","severity":"HIGH","publishedAt":"2026-10-12T21:17:22.213Z"},"summary":"New CVE, high severity (CVSS 8.8)."}],"references":[{"url":"https://github.com/0xJacky/nginx-ui/commit/23d1934099b05b2a01589b48129dc3d3159d91c2","source":"security-advisories@github.com"},{"url":"https://github.com/0xJacky/nginx-ui/releases/tag/v2.4.1","source":"security-advisories@github.com"},{"url":"https://github.com/0xJacky/nginx-ui/security/advisories/GHSA-76pm-mq2q-9gcr","source":"security-advisories@github.com"},{"url":"https://github.com/0xJacky/nginx-ui/security/advisories/GHSA-76pm-mq2q-9gcr","source":"134c704f-9b21-4f2e-91b3-4a467353bcc0"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-84317","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}