← Vulnerability feed

Vulnerability record · CVE-2023-51701 · published 8 January 2024

CVE-2023-51701: Fastify reply-from http request smuggling vulnerability

Fastify · Reply From

fastify-reply-from is a Fastify plugin to forward the current HTTP request to another server. A reverse proxy server built with `@fastify/reply-from` could misinterpret the incoming body by passing an header `ContentType: application/json ; charset=utf-8`. This can lead to bypass of security checks. This vulnerability has been patched in '@fastify/reply-from` version 9.6.0.

7.5 CVSS 3.1 High EPSS 0.48% · top 61.1% CWE-444 · HTTP request smuggling
7.5CVSS 3.1 base score
0.48%EPSS exploitation probability, 30 days
NoNot in CISA KEV
1Affected product versions listed by NVD
4References
17 Jun 2026Last modified by NVD

Description

fastify-reply-from is a Fastify plugin to forward the current HTTP request to another server. A reverse proxy server built with `@fastify/reply-from` could misinterpret the incoming body by passing an header `ContentType: application/json ; charset=utf-8`. This can lead to bypass of security checks. This vulnerability has been patched in '@fastify/reply-from` version 9.6.0.

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N

Affected products

1 vulnerable configurations from NVD's CPE data, grouped by vendor and product.

References

LinkTags
https://github.com/fastify/fastify-reply-from/releases/tag/v9.6.0 Release Notes
https://github.com/fastify/fastify-reply-from/security/advisories/GHSA-v2v2-hph8-q5xp Vendor Advisory
https://github.com/fastify/fastify-reply-from/releases/tag/v9.6.0 Release Notes
https://github.com/fastify/fastify-reply-from/security/advisories/GHSA-v2v2-hph8-q5xp Vendor Advisory

Track CVE-2023-51701 inside VULONE

Watch it alongside the ransomware crews, C2 infrastructure and forum chatter that reference it, query it through the API and pull it into your SIEM over TAXII.

Start free Open in platform

Related vulnerabilities

Same products first, then exploited flaws of the same weakness class.

9.0CVE-2026-33805Fastify\/http-proxy http request smuggling vulnerability@fastify/reply-from v12.6.1 and earlier and @fastify/http-proxy v11.4.3 and earlier process the client's Connection header after the proxy has added …EPSS 0.56%6.9CVE-2025-66415Fastify reply-from vulnerabilityfastify-reply-from is a Fastify plugin to forward the current HTTP request to another server. Prior to 12.5.0, by crafting a malicious URL, an attack…EPSS 0.18%6.5CVE-2026-48710Starlette Host header validation flaw enables request.url path mismatchStarlette before 1.0.1 did not validate the HTTP Host header before using it to rebuild request.url, so a malformed Host value could make request.url…KEVEPSS 7.1%analysed7.5CVE-2025-61884Oracle E-Business Suite Configurator pre-auth data exposure flawOracle Configurator in Oracle E-Business Suite 12.2.3 through 12.2.14 exposes a vulnerability reachable over HTTP without authentication. A successfu…KEVEPSS 96%analysed9.9CVE-2023-48365Qlik Sense Enterprise HTTP Request Smuggling Enables Unauthenticated RCEQlik Sense Enterprise for Windows before August 2023 Patch 2 fails to properly validate HTTP headers, allowing HTTP request tunneling to the backend …KEVEPSS 47%analysed9.9CVE-2023-41265Qlik Sense Enterprise HTTP request tunneling privilege escalationQlik Sense Enterprise for Windows fails to properly handle raw HTTP requests, allowing request tunneling that reaches the backend repository applicat…KEVEPSS 88%analysed10.0CVE-2022-22536SAP NetWeaver and Web Dispatcher HTTP request smugglingSAP NetWeaver Application Server ABAP, NetWeaver Application Server Java, ABAP Platform, Content Server 7.53 and Web Dispatcher mishandle HTTP reques…KEVEPSS 98%analysed

Source: NIST National Vulnerability Database (record CVE-2023-51701), CISA KEV, FIRST EPSS (scores of 2026-09-27). This page is refreshed as NVD updates the record.