Nodejs Undici vulnerabilities
46 vulnerabilities
Known vulnerabilities in Nodejs Undici, newest first, with CVSS severity, EPSS, KEV listings, ransomware use and the affected versions.
CVE-2025-47279chainguardcode-server+7
EPSS score0.34%
Undici is an HTTP/1.1 client for Node.js. Prior to versions 5.29.0, 6.21.2, and 7.5.0, applications that use undici to implement a webhook-like system are vulnerable. If the attacker set up a server with an invalid certificate, and they can force the application to call the webhook repeatedly, then they can cause a memory leak. This has been patched in versions 5.29.0, 6.21.2, and 7.5.0. As a workaound, avoid calling a webhook repeatedly if the webhook fails.CVE-2025-22150alpinenodejs+6EPSS score0.76%
Undici is an HTTP/1.1 client. Starting in version 4.5.0 and prior to versions 5.28.5, 6.21.1, and 7.2.3, undici uses `Math.random()` to choose the boundary for a multipart/form-data request. It is known that the output of `Math.random()` can be predicted if several of its generated values are known. If there is a mechanism in an app that sends multipart requests to an attacker-controlled website, they can use this to leak the necessary values. Therefore, an attacker can tamper with the requests going to the backend APIs if certain conditions are met. This is fixed in versions 5.28.5, 6.21.1, and 7.2.3. As a workaround, do not issue multipart requests to attacker controlled servers.CVE-2022-31151debiannode-undici+3EPSS score0.74%
Authorization headers are cleared on cross-origin redirect. However, cookie headers which are sensitive headers and are official headers found in the spec, remain uncleared. There are active users using cookie headers in undici. This may lead to accidental leakage of cookie to a 3rd-party site or a malicious attacker who can control the redirection target (ie. an open redirector) to leak the cookie to the 3rd party site. This was patched in v5.7.1. By default, this vulnerability is not exploitable. Do not enable redirections, i.e. `maxRedirections: 0` (the default).CVE-2022-31150debiannode-undici+3EPSS score1.52%
undici is an HTTP/1.1 client, written from scratch for Node.js. It is possible to inject CRLF sequences into request headers in undici in versions less than 5.7.1. A fix was released in version 5.8.0. Sanitizing all HTTP headers from untrusted sources to eliminate `\r\n` is a workaround for this issue.CVE-2022-32210debiannode-undici+2EPSS score0.47%
`Undici.ProxyAgent` never verifies the remote server's certificate, and always exposes all request & response data to the proxy. This unexpectedly means that proxies can MitM all HTTPS traffic, and if the proxy's URL is HTTP then it also means that nominally HTTPS requests are actually sent via plain-text HTTP between Undici and the proxy server.CVE-2022-35949debiannode-undici+2EPSS score1.87%
undici is an HTTP/1.1 client, written from scratch for Node.js.`undici` is vulnerable to SSRF (Server-side Request Forgery) when an application takes in **user input** into the `path/pathname` option of `undici.request`. If a user specifies a URL such as `http://127.0.0.1` or `//127.0.0.1` ```js const undici = require("undici") undici.request({origin: "http://example.com", pathname: "//127.0.0.1"}) ``` Instead of processing the request as `http://example.org//127.0.0.1` (or `http://example.org/http://127.0.0.1` when `http://127.0.0.1 is used`), it actually processes the request as `http://127.0.0.1/` and sends it to `http://127.0.0.1`. If a developer passes in user input into `path` parameter of `undici.request`, it can result in an _SSRF_ as they will assume that the hostname cannot change, when in actual fact it can change because the specified path parameter is combined with the base URL. This issue was fixed in `undici@5.8.1`. The best workaround is to validate user input before passing it to the `undici.request` call.CVE-2022-35948debiannode-undici+2EPSS score1.35%
undici is an HTTP/1.1 client, written from scratch for Node.js.`=< undici@5.8.0` users are vulnerable to _CRLF Injection_ on headers when using unsanitized input as request headers, more specifically, inside the `content-type` header. Example: ``` import { request } from 'undici' const unsanitizedContentTypeInput = 'application/json\r\n\r\nGET /foo2 HTTP/1.1' await request('http://localhost:3000, { method: 'GET', headers: { 'content-type': unsanitizedContentTypeInput }, }) ``` The above snippet will perform two requests in a single `request` API call: 1) `http://localhost:3000/` 2) `http://localhost:3000/foo2` This issue was patched in Undici v5.8.1. Sanitize input when sending content-type headers using user input as a workaround.CVE-2024-38372ubuntunode-undici+2EPSS score0.47%
Undici is an HTTP/1.1 client, written from scratch for Node.js. Depending on network and process conditions of a `fetch()` request, `response.arrayBuffer()` might include portion of memory from the Node.js process. This has been patched in v6.19.2.CVE-2024-24758debiannode-undici+3EPSS score0.77%
Undici is an HTTP/1.1 client, written from scratch for Node.js. Undici already cleared Authorization headers on cross-origin redirects, but did not clear `Proxy-Authentication` headers. This issue has been patched in versions 5.28.3 and 6.6.1. Users are advised to upgrade. There are no known workarounds for this vulnerability.CVE-2024-24750ubuntunode-undici+2EPSS score0.70%
Undici is an HTTP/1.1 client, written from scratch for Node.js. In affected versions calling `fetch(url)` and not consuming the incoming body ((or consuming it very slowing) will lead to a memory leak. This issue has been addressed in version 6.6.1. Users are advised to upgrade. Users unable to upgrade should make sure to always consume the incoming body.CVE-2024-30261debiannode-undici+5EPSS score0.80%
Undici is an HTTP/1.1 client, written from scratch for Node.js. An attacker can alter the `integrity` option passed to `fetch()`, allowing `fetch()` to accept requests as valid even if they have been tampered. This vulnerability was patched in version(s) 5.28.4 and 6.11.1.CVE-2024-30260debiannode-undici+5EPSS score0.73%
Undici is an HTTP/1.1 client, written from scratch for Node.js. Undici cleared Authorization and Proxy-Authorization headers for `fetch()`, but did not clear them for `undici.request()`. This vulnerability was patched in version(s) 5.28.4 and 6.11.1.CVE-2026-16729chainguardactions-runner+51EPSS score0.19%
undici's setCookie function does not fully sanitize cookie attributes. In undici before 6.28.0, from 7.0.0 up to before 7.29.0, and from 8.0.0 up to before 8.9.0, a domain value is not checked for semicolons and entries in the unparsed array are not sanitized, so attacker-influenced input can inject additional cookie attributes. For example, a domain value containing a semicolon can append attributes such as SameSite, and an unparsed entry can inject attributes such as HttpOnly, without the caller setting them. Applications that pass user-controlled input to these fields, such as multi-tenant or reverse-proxy servers that scope session cookies to a tenant-supplied domain, can have SameSite CSRF protections bypassed, or the Secure, HttpOnly, and SameSite attributes forced, stripped, or overridden. The issue is fixed in undici 6.28.0, 7.29.0, and 8.9.0.CVE-2026-16728chainguardactions-runner+51EPSS score0.18%
undici's retry interceptor can deliver a response whose body length does not match the Content-Length header exposed to the application after a retry or resume of a partial response. In undici before 6.28.0, from 7.0.0 up to before 7.29.0, and from 8.0.0 up to before 8.9.0, a malicious or faulty upstream can return a partial response with a mismatched framing header, close the socket early, and have the retry interceptor assemble a body of a different length while the original Content-Length stays attached. Applications that use the retry interceptor and forward upstream headers and bodies downstream, such as proxies or gateways, may then emit an invalid HTTP response with a stale Content-Length, leading to downstream response desynchronization, connection hangs, or response corruption. Exploitation requires the retry interceptor enabled, an upstream returning a mismatched partial response, and a downstream forwarder that does not remove or recalculate Content-Length. The issue is fixed in undici 6.28.0, 7.29.0, and 8.9.0.CVE-2026-2229chainguardcode-server+37EPSS score0.89%
ImpactThe undici WebSocket client is vulnerable to a denial-of-service attack due to improper validation of the server_max_window_bits parameter in the permessage-deflate extension. When a WebSocket client connects to a server, it automatically advertises support for permessage-deflate compression. A malicious server can respond with an out-of-range server_max_window_bits value (outside zlib's valid range of 8-15). When the server subsequently sends a compressed frame, the client attempts to create a zlib InflateRaw instance with the invalid windowBits value, causing a synchronous RangeError exception that is not caught, resulting in immediate process termination.
The vulnerability exists because:
* The isValidClientWindowBits() function only validates that the value contains ASCII digits, not that it falls within the valid range 8-15
* The createInflateRaw() call is not wrapped in a try-catch block
* The resulting exception propagates up through the call stack and crashes the Node.js processCVE-2026-2581chainguardcode-server+21EPSS score0.74%
This is an uncontrolled resource consumption vulnerability (CWE-400) that can lead to Denial of Service (DoS).
In vulnerable Undici versions, when interceptors.deduplicate() is enabled, response data for deduplicated requests could be accumulated in memory for downstream handlers. An attacker-controlled or untrusted upstream endpoint can exploit this with large/chunked responses and concurrent identical requests, causing high memory usage and potential OOM process termination.
Impacted users are applications that use Undici’s deduplication interceptor against endpoints that may produce large or long-lived response bodies.
PatchesThe issue has been patched by changing deduplication behavior to stream response chunks to downstream handlers as they arrive (instead of full-body accumulation), and by preventing late deduplication when body streaming has already started.
Users should upgrade to the first official Undici (and Node.js, where applicable) releases that include this patch.CVE-2026-13697chainguardcode-server+39EPSS score0.57%
undici's cache interceptor mishandles malformed Cache-Control private directives. In undici 7.0.0 up to before 7.29.0 and 8.0.0 up to before 8.9.0, a response carrying a degenerate qualified private directive, such as private set to an empty value, can be stored in the default shared cache and later served to a different caller with the same cache key, disclosing private response bodies and headers including Set-Cookie. Separately, a Cache-Control header that combines an unqualified private directive with a qualified one triggers an uncaught TypeError in the cache-control parser, which rejects the request and, depending on the consumer's error handling, can terminate the process. Both issues affect applications using the cache interceptor in shared mode, including the default configuration. The issues are fixed in undici 7.29.0 and 8.9.0.CVE-2026-84947chainguardcode-server+22EPSS score0.20%
undici's dump interceptor reads and discards a response body up to a configurable maximum size. When a response declares a Content-Length that exceeds the maximum, the interceptor aborts cleanly, but when a response has no Content-Length and is chunked, the interceptor instead signals completion early once the accumulated size reaches the maximum, without pausing or aborting the request. Because the underlying parser keeps delivering body bytes, a second completion signal fires and trips an internal assertion, which aborts the request and tears down the connection. The application is left observing a misleading successful status with an empty or truncated body while the connection has actually been disconnected. This affects undici versions from 7.1.0 up to 7.29.1 and from 8.0.0 up to 8.10.2. Users should upgrade to undici 7.29.1 or 8.10.2.CVE-2026-84890chainguardcode-server+22EPSS score0.41%
undici's decompress interceptor decompresses response bodies according to the untrusted Content-Encoding header. While the number of content-encoding layers is capped, the total decompressed output size is unbounded and there is no configuration option to limit it. A malicious or faulty upstream can therefore return a small compressed payload, a compression bomb, that expands to hundreds of megabytes or more in client memory, an asymmetric resource consumption that can exhaust memory and crash the process. This affects undici versions from 7.15.0 up to 7.29.1 and from 8.0.0 up to 8.10.2. Users should upgrade to undici 7.29.1 or 8.10.2.CVE-2026-84961chainguardcode-server+22EPSS score0.15%
undici's BalancedPool constructor passes its entire options object through an internal deep-clone that serializes and reparses the value as JSON. Because JSON cannot represent functions, any function-valued TLS option, such as a caller-supplied checkServerIdentity callback or a custom connector inside the connect option, is silently discarded before it reaches the TLS layer. As a result a peer whose certificate the application's custom checkServerIdentity was written to reject, but which still passes Node's default hostname and chain checks, is accepted when reached through BalancedPool. The Client, Pool, and Agent dispatchers are not affected because they extract the connect and tls options before cloning. This affects undici versions from 7.24.1 up to 7.29.1 and from 8.0.0 up to 8.10.2, and only when the application supplies a function-valued connect or tls option to BalancedPool. Users should upgrade to undici 7.29.1 or 8.10.2.