CVE-2026-120213
Last modified
CVE-2026-120213 is a critical-severity vulnerability rated 9.1/10 on the CVSS scale. @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.
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.
Metrics
Weakness Enumeration
Affected Software
Source: CNA advisory (CVE.org). NVD analysis pending.
| Vendor | Product | Versions |
|---|---|---|
| @fastify/http-proxy | @fastify/http-proxy | >= 9.0.0, < 11.6.6 |
References
Timeline
- Published
- Last Modified
- Status
- Awaiting Analysis
Frequently Asked Questions
What is CVE-2026-120213?
How severe is CVE-2026-120213?
How do I fix CVE-2026-120213?
How Strix Helps
- How Strix found a critical auth bypass in etcdStrix autonomously discovered a critical authentication bypass in etcd, later designated CVE-2026-33413.
- Autonomous PentestingAI agents that find and validate exploitable vulnerabilities like this one across your applications.
- PR ReviewsPentest every pull request so vulnerable code is caught before it ships to production.
- AI Penetration TestingHow AI-driven penetration testing continuously covers your attack surface.
Related CVEs from 2026
- CVE-2026-120205Thelia before 3.1.0 contains a stored cross-site scripting v…8
- CVE-2026-120206Thelia before 3.2.0 contains a cross-site request forgery vu…5.9
- CVE-2026-120207Thelia Page Module before 2.0.4 contains a cross-site reques…7.1
- CVE-2026-120208libheif 1.18.0 before 1.23.3 contains a heap-based buffer ov…7.5
- CVE-2026-120209AJ-Report through 1.7.1 signs share tokens with a hard-coded…9.8
- CVE-2026-120210FFmpeg 5.0 through 9.0.2 contains a path traversal vulnerabi…4.3
- CVE-2026-120214@fastify/http-proxy is a Fastify plugin that proxies HTTP re…5.9
- CVE-2026-120215@fastify/cors is the CORS plugin for the Fastify web framewo…3.7
- CVE-2026-120216fastify is a web framework for Node.js. In versions 5.8.0 th…5.9
- CVE-2026-120217A vulnerability was detected in Delgan loguru 0.7.3. The aff…4.3
- CVE-2026-120218A flaw has been found in Typemill up to 2.26.0. The impacted…3.5
- CVE-2026-12022Race in Safe Browsing in Google Chrome on Mac prior to 149.0…8.3
Are you affected by CVE-2026-120213?
Run a free Strix scan to check your systems for this vulnerability.
Scan your code nowSource: NVD / NIST
