nodejs Evented IO for v8 JavaScript

Recent nodejs Security Advisories

By the Year

In 2026 there have been 19 vulnerabilities in nodejs with an average score of 6.4 out of ten. Last year, in 2025 nodejs had 6 security vulnerabilities published. That is, 13 more vulnerabilities have already been reported in 2026 as compared to last year. However, the average CVE base score of the vulnerabilities in 2026 is greater by 3.33.

Recent nodejs Security Vulnerabilities

CVE	Date	Vulnerability	Products
CVE-2026-21710	Mar 30, 2026	Node.js HTTP __proto__ Header Injection Causing Uncaught TypeError A flaw in Node.js HTTP request handling causes an uncaught `TypeError` when a request is received with a header named `__proto__` and the application accesses `req.headersDistinct`. When this occurs, `dest["__proto__"]` resolves to `Object.prototype` rather than `undefined`, causing `.push()` to be called on a non-array. This exception is thrown synchronously inside a property getter and cannot be intercepted by `error` event listeners, meaning it cannot be handled without wrapping every `req.headersDistinct` access in a `try/catch`. * This vulnerability affects all Node.js HTTP servers on **20.x, 22.x, 24.x, and v25.x**
CVE-2026-21715	Mar 30, 2026	Node.js Permission Model Bypass via fs.realpathSync.native() A flaw in Node.js Permission Model filesystem enforcement leaves `fs.realpathSync.native()` without the required read permission checks, while all comparable filesystem functions correctly enforce them. As a result, code running under `--permission` with restricted `--allow-fs-read` can still use `fs.realpathSync.native()` to check file existence, resolve symlink targets, and enumerate filesystem paths outside of permitted directories. This vulnerability affects **20.x, 22.x, 24.x, and 25.x** processes using the Permission Model where `--allow-fs-read` is intentionally restricted.
CVE-2026-21711	Mar 30, 2026	Node.js 25.x Permission Model Bypass Exploiting UDS A flaw in Node.js Permission Model network enforcement leaves Unix Domain Socket (UDS) server operations without the required permission checks, while all comparable network paths correctly enforce them. As a result, code running under `--permission` without `--allow-net` can create and expose local IPC endpoints, allowing communication with other processes on the same host outside of the intended network restriction boundary. This vulnerability affects Node.js **25.x** processes using the Permission Model where `--allow-net` is intentionally omitted to restrict network access. Note that `--allow-net` is currently an experimental feature.
CVE-2026-21716	Mar 30, 2026	Node.js FileHandle Promise API Bypass in PermissionModel An incomplete fix for CVE-2024-36137 leaves `FileHandle.chmod()` and `FileHandle.chown()` in the promises API without the required permission checks, while their callback-based equivalents (`fs.fchmod()`, `fs.fchown()`) were correctly patched. As a result, code running under `--permission` with restricted `--allow-fs-write` can still use promise-based `FileHandle` methods to modify file permissions and ownership on already-open file descriptors, bypassing the intended write restrictions. This vulnerability affects **20.x, 22.x, 24.x, and 25.x** processes using the Permission Model where `--allow-fs-write` is intentionally restricted.
CVE-2026-21714	Mar 30, 2026	Node.js HTTP/2 Memory Leak via WINDOW_UPDATE Overflow A memory leak occurs in Node.js HTTP/2 servers when a client sends WINDOW_UPDATE frames on stream 0 (connection-level) that cause the flow control window to exceed the maximum value of 2³¹-1. The server correctly sends a GOAWAY frame, but the Http2Session object is never cleaned up. This vulnerability affects HTTP2 users on Node.js 20, 22, 24 and 25.
CVE-2026-21713	Mar 30, 2026	Node.js HMAC Timing Oracle Exploit (CVE-2026-21713) A flaw in Node.js HMAC verification uses a non-constant-time comparison when validating user-provided signatures, potentially leaking timing information proportional to the number of matching bytes. Under certain threat models where high-resolution timing measurements are possible, this behavior could be exploited as a timing oracle to infer HMAC values. Node.js already provides timing-safe comparison primitives used elsewhere in the codebase, indicating this is an oversight rather than an intentional design decision. This vulnerability affects **20.x, 22.x, 24.x, and 25.x**.
CVE-2026-21717	Mar 30, 2026	V8 String Hash Collision DoS in Node.js via JSON.parse A flaw in V8's string hashing mechanism causes integer-like strings to be hashed to their numeric value, making hash collisions trivially predictable. By crafting a request that causes many such collisions in V8's internal string table, an attacker can significantly degrade performance of the Node.js process. The most common trigger is any endpoint that calls `JSON.parse()` on attacker-controlled input, as JSON parsing automatically internalizes short strings into the affected hash table. This vulnerability affects **20.x, 22.x, 24.x, and 25.x**.
CVE-2026-21712	Mar 30, 2026	Node.js URL.format() Crash via Malformed IDN A flaw in Node.js URL processing causes an assertion failure in native code when `url.format()` is called with a malformed internationalized domain name (IDN) containing invalid characters, crashing the Node.js process.
CVE-2026-2229	Mar 12, 2026	Undici <7.24.0: Invalid permessage-deflate server_max_window_bits Causes DoS 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 process	Undici
CVE-2026-2581	Mar 12, 2026	Undici deduplication interceptor memory OOM | 7.23 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 Undicis 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.	Undici