{"cve":"CVE-2026-120213","nvd":{"published":"2026-11-02T11:17:31.137","modified":"2026-11-02T11:17:31.137","status":"Received","description":"@fastify/http-proxy is a Fastify plugin that proxies HTTP requests to an upstream server under a configured prefix. In versions 9.0.0 through 11.6.5, when an application uses parameterized prefix and rewritePrefix options to pin clients to a fixed upstream path, the plugin substitutes URL-decoded route parameters into rewritePrefix without re-encoding them. A parameter value that encodes a path separator together with a fragment or query delimiter therefore decodes into real separators and delimiters that inject extra upstream path segments and strip the mandatory suffix the rewritePrefix was meant to enforce, without using any dot-dot traversal. An unauthenticated remote attacker can use this to reach upstream locations outside the intended prefix, leading to path-restriction bypass and, depending on the upstream, server-side request forgery or authorization bypass in the proxied service. The issue is fixed in @fastify/http-proxy 11.6.6, and users should upgrade to 11.6.6 or later. There is no workaround other than upgrading.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N","score":9.1},"cwes":["CWE-22","CWE-436"],"references":["https://cna.openjsf.org/security-advisories.html","https://github.com/fastify/fastify-http-proxy/security/advisories/GHSA-h3vp-4jfr-v364"],"reference_tags":[{"url":"https://cna.openjsf.org/security-advisories.html","tags":[]},{"url":"https://github.com/fastify/fastify-http-proxy/security/advisories/GHSA-h3vp-4jfr-v364","tags":[]}],"products":[],"affected":[],"source":"nvd","synced_at":"2026-11-02T11:46:51.329548709+00:00"},"epss":null,"kev":null,"exploits":[],"weaknesses":[{"name":"Improper Limitation of a Pathname to a Restricted Directory","common_name":"Path traversal","deprecated":false,"replaced_by":[],"id":"CWE-22"},{"name":"Interpretation Conflict","common_name":null,"deprecated":false,"replaced_by":[],"id":"CWE-436"}],"osv":[],"fixed":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program.","Public exploits: links to the Exploit Database (https://www.exploit-db.com, by OffSec; index under GPL-2.0), Rapid7's Metasploit Framework modules (https://github.com/rapid7/metasploit-framework, BSD-3-Clause) and ProjectDiscovery's nuclei templates (https://github.com/projectdiscovery/nuclei-templates, MIT). Only the links, titles and dates are stored; no exploit code is fetched or served.","CWE names and descriptions: MITRE's Common Weakness Enumeration (https://cwe.mitre.org), Copyright © 2006–2026, The MITRE Corporation, under the CWE terms of use (https://cwe.mitre.org/about/termsofuse.html). CWE is a trademark of The MITRE Corporation."]}