Improper Neutralization of HTTP Headers for Scripting Syntax

Monkeytype is a minimalistic and customizable typing test. In 26.26.0 and earlier, the backend rate-limit key generator in backend/src/middlewares/rate-limit.ts uses client-controlled cf-connecting-ip and x-forwarded-for headers before the trust-proxy-derived req.ip value. An unauthenticated attacker can rotate either header to create a new bucket for each request, bypassing rootRateLimiter, badAuthRateLimiter, getKey(), and the getKeyWithUid() fallback used by public endpoints. This permits repeated POST /users/forgotPasswordEmail and verificationEmail requests, mail bombing registered users, consuming Firebase or SMTP quota, evading brute-force protection, and enabling resource exhaustion. Exploitability of cf-connecting-ip depends on deployment topology, but x-forwarded-for and direct-to-origin paths remain affected when those values are not overwritten by a trusted proxy. No fixed version is available as of this review.Show less

Genkit does not properly validate host request headers. Any host on the developer's network, and any website the developer visits (via DNS rebinding), can reach POST /api/runAction on the Dev UI server (default port 4000) and execute any registered Genkit action and read the result. Fixed on 2026-06-18.Show less

SAP Approuter does not sufficiently sanitize certain request headers before forwarding traffic to internal components. An unauthenticated attacker could send a specially crafted request to obtain limited unauthorized access to information. This results in a low impact on confidentiality. There is no impact on integrity and availability.Show less

A host header injection vulnerability in picocms/Pico through 2.1.4 allows an unauthenticated remote attacker to control the origin of JavaScript and CSS assets loaded by the default theme. When base_url is unset (the default), Pico::getBaseUrl in lib/Pico.php builds the base URL from unvalidated Host, X-Forwarded-Host, X-Forwarded-Proto, and X-Forwarded-Port request headers.Show less

Litestar is an Asynchronous Server Gateway Interface (ASGI) framework. In versions prior to 2.22.0, an attacker can bypass the allowed hosts validation by omitting the Host header and supplying an X-Forwarded-Host header set to a whitelisted domain. The AllowedHostsMiddleware trusts the X-Forwarded-Host header as a fallback when the Host header is absent. Since X-Forwarded-Host is a client-controllable header, this enables host header injection attacks such as password reset poisoning, cache poisoning, and server-side request routing manipulation. Any application using AllowedHostsConfig is affected when deployed without a reverse proxy that strips X-Forwarded-Host, or when accepting HTTP/1.0 connections. This issue has been fixed in version 2.22.0.Show less

Craft CMS is a content management system (CMS). Versions 4.0.0-RC1 and above, prior to 4.18.0 and 5.0.0-RC1, and above, prior to 5.10.0, are vulnerable to Server-Side Request Forgery (SSRF) and Arbitrary JavaScript Injection through the /actions/app/resource-js endpoint. By exploiting the default permissive trustedHosts configuration, an attacker can poison the Host or X-Forwarded-Host header to manipulate the application’s $baseUrl. This bypasses the endpoint’s internal URL validation, forcing the backend Guzzle client to fetch a malicious payload from an attacker-controlled server and reflect it to the client with a Content-Type: application/javascript header. The vulnerability manifests when assetManager.cacheSourcePaths is set to false. This issue has been fixed in versions 4.18.0 and 5.10.0.Show less

IBM Engineering Workflow Management 7.0.2 through 7.0.2 Interim Fix 035, 7.0.3 through 7.0.3 Interim Fix 017, and 7.1 through 7.1 Interim Fix 004 is vulnerable to HTTP header injection, caused by improper validation of input by the HOST headers. This could allow an attacker to conduct various attacks against the vulnerable system, including cross-site scripting, cache poisoning or session hijacking.Show less

Improper handling of HTTP headers that allows a remote attacker to manipulate the value of the Host header using specially crafted requests. A successful exploit could result in the generation of manipulated links or responses, potentially leading to limited information disclosure or compromising the integrity of dependent services.Show less

IBM DevOps Plan 3.0.0 through 3.0.6 is vulnerable to HTTP header injection, caused by improper validation of input by the HOST headers. This could allow an attacker to conduct various attacks against the vulnerable system, including cross-site scripting, cache poisoning or session hijackingShow less

Algernon is a small self-contained pure-Go web server. Prior to 1.17.8, when algernon is started with --domain (or --letsencrypt, which silently turns on --domain at engine/flags.go:372), the request handler resolves the served directory by joining the configured --dir with the value of the client-supplied Host header. The join is performed by filepath.Join with no validation, so a Host: .. header walks one level above the document root. Subsequent file resolution then exposes everything in that parent directory — arbitrary file read, full directory listing, and, if any .lua file is present, server-side Lua execution. This vulnerability is fixed in 1.17.8.Show less

@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 its own headers via rewriteRequestHeaders. This allows attackers to retroactively strip proxy-added headers from upstream requests by listing them in the Connection header value. Any header added by the proxy for routing, access control, or security purposes can be selectively removed by a client. @fastify/http-proxy is also affected as it delegates to @fastify/reply-from. Upgrade to @fastify/reply-from v12.6.2 or @fastify/http-proxy v11.4.4 or later.Show less

IBM Aspera Shares 1.9.9 through 1.11.0 is vulnerable to HTTP header injection, caused by improper validation of input by the HOST headers.  This could allow an attacker to conduct various attacks against the vulnerable system, including cross-site scripting, cache poisoning or session hijacking.Show less

Tandoor Recipes is an application for managing recipes, planning meals, and building shopping lists. Versions up to and including 2.5.3 set ALLOWED_HOSTS = '*' by default, which causes Django to accept any value in the HTTP Host header without validation. The application uses request.build_absolute_uri() to generate absolute URLs in multiple contexts, including invite link emails, API pagination, and OpenAPI schema generation. An attacker who can send requests to the application with a crafted Host header can manipulate all server-generated absolute URLs. The most critical impact is invite link poisoning: when an admin creates an invite and the application sends the invite email, the link points to the attacker's server instead of the real application. When the victim clicks the link, the invite token is sent to the attacker, who can then use it at the real application. As of time of publication, it is unknown if a patched version is available.Show less

IBM InfoSphere Information Server 11.7.0.0 through 11.7.1.6 is vulnerable to HTTP header injection, caused by improper validation of input by the HOST headers. This could allow an attacker to conduct various attacks against the vulnerable system, including cross-site scripting, cache poisoning or session hijacking.Show less

IBM Aspera Orchestrator 3.0.0 through 4.1.2 is vulnerable to HTTP header injection, caused by improper validation of input by the HOST headers. This could allow an attacker to conduct various attacks against the vulnerable system, including cross-site scripting, cache poisoning or session hijackingShow less

IBM Aspera Faspex 5 5.0.0 through 5.0.14.3 is vulnerable to HTTP header injection, caused by improper validation of input by the HOST headers.  This could allow an attacker to conduct various attacks against the vulnerable system, including cross-site scripting, cache poisoning or session hijacking.Show less