Vulnerability · CVE-2026-84318
Nginx UI: MCP Bypasses Directive Validation — Authenticated RCE
Published Oct 15, 2026 · Nginx UI: MCP Bypasses
Check if you run it
No confirmed exploitation is on record for CVE-2026-84318. EPSS is 0.62%. Act only if a listed version of Nginx UI: MCP Bypasses is installed.
Gaps on this record
- The stored product name is a package slug. The name on this page is taken from the title (Nginx UI: MCP Bypasses).
- No version range is stored. A customer cannot check an installed version against this record.
- No vendor fix or required action is stored. Compare the linked advisory before you change production.
- Severity
- Unknown—
- Known exploitation
- Not in CISA/VulnCheck KEV
- EPSS
- 0.62%
- Remediation
- Not established
- Affected products
- golang github.com
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, …
Are you affected?
Enter the version you run. The result uses only the ranges stored on this record.
The check returns affected, not affected, or incomplete. It does not guess a version that is missing from the record.
- golang github.comversion unspecified
How to fix CVE-2026-84318
Recommended remediation
No required-action text, fix commit, or clear fixed-version range is stored yet.
Official advisories
What to do
Three questions, each answered from this record only. Confirm the vendor advisory before you patch.
Should you patch?
No confirmed exploitation is on record for CVE-2026-84318. EPSS is 0.62%. Act only if a listed version of Nginx UI: MCP Bypasses is installed.
Which versions are affected?
Affected version ranges are not on this record. Compare the installed version with the linked vendor advisory before you change production.
What should an analyst verify?
No weakness class is stored. EPSS 0.62%. There is no CISA KEV listing. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.
Code
The project this record applies to. Exploit listings stay in References.
No public source repository is identified for this product.
Timeline
Detection, updates, and resolution for this record.
Oct 15, 2026 · GitLab Advisory Database
Detected
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, u
Sources
- CVE.orgVulnerability recordCVE-2026-84318
Official CVE identifier
cve.org - FIRST EPSSExploitation probabilityCVE-2026-84318
30-day exploitation probability 0.6%
first.org - GitLab Advisory DatabasePackage advisoryCVE-2026-84318
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, u
advisories.gitlab.com
Freshness
Last verified in this catalog Oct 18, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.