Denoland

Deno is a JavaScript, TypeScript, and WebAssembly runtime with secure defaults. When you send a request with the Authorization header to one domain, and the response asks to redirect to a different domain, Deno'sfetch() redirect handling creates a follow-up redirect request that…

@std/toml is the Deno Standard Library. Prior to version 1.0.9, an attacker can pollute the prototype chain in Node.js runtime and Browser when parsing untrusted TOML data, thus achieving Prototype Pollution (PP) vulnerability. This is because the library is merging an untrusted…

## Summary `node:crypto.checkPrime(candidate[, options][, callback])` and `crypto.checkPrimeSync(candidate[, options])` ran no Miller-Rabin rounds at all when the caller left `options.checks` at its default of `0`. In that mode, the only test applied to the candidate was trial…

## Summary Deno's `node:child_process` implementation provided an `escapeShellArg()` helper used when callers passed `shell: true` to `spawn` / `spawnSync` / `exec` and friends. On Windows, the helper failed to quote arguments that contained `cmd.exe` metacharacters such as…

## Summary A flaw in Deno's Node.js tls compatibility layer could cause a TLS client to transmit application data in plaintext after a connection retry. When `autoSelectFamily was enabled and the first address-family attempt failed, the socket reinitialization path reused a…

The Deno Standard Library provides APIs for Deno and the Web. Prior to version 1.0.11, `http/file-server`'s `serveDir` with `showDirListing: true` option is vulnerable to cross-site scripting when the attacker is a user who can control file names in the source directory on…

Deno is a runtime for JavaScript and TypeScript written in rust. Several cross-site scripting vulnerabilities existed in the `deno_doc` crate which lead to Self-XSS with deno doc --html. 1.) XSS in generated `search_index.js`, `deno_doc` outputs a JavaScript file for searching.…

### Summary Static imports are exempted from the network permission check. An attacker could exploit this to leak the password file on the network. ### Details Static imports in Deno are exempted from the network permission check. This can be exploited by attackers in…

## Summary A Deno program that opens a client `WebSocket` connection could be crashed by the remote server. While handling the WebSocket handshake response, Deno parsed the `Sec-WebSocket-Protocol` and `Sec-WebSocket-Extensions` response headers in a way that assumed their…

## Summary Deno's permission system enforces filesystem and execution restrictions by comparing the requested path against the path supplied to `--deny-read`, `--deny-write`, `--deny-run`, or `--deny-ffi`. On macOS, that comparison was done at the raw-byte level while the APFS…

## Summary When Deno was run in BYONM mode (`nodeModulesDir: "manual"`), the module resolver did not validate that a package's resolved entrypoint stayed within its `node_modules//` directory. A malicious `package.json` whose `main` field contained `..` segments was able…

## Summary Deno's network permission model is designed so that `--deny-net` rules apply to the **resolved IP address** of a destination, not just the literal string supplied by the caller. That means `--deny-net=127.0.0.1` (or `--deny-net=127.0.0.0/8`) is expected to block any…

## Summary In Deno, environment access is gated by the `env` permission. You can deny it with `--deny-env`, or restrict it to a specific allowlist with `--allow-env=FOO,BAR`. The expectation is that a program running without `env` permission cannot change `process.env`. …

## Summary When a WebSocket connection was opened, Deno checked the destination hostname against `--deny-net` rules but did not re-check the IP addresses that hostname resolved to. An attacker-controlled script could use a specially crafted domain name that passes the hostname…

## Summary When `fetch()` was called, Deno checked the destination hostname against `--deny-net` rules but did not re-check the IP addresses that hostname resolved to. An attacker-controlled script could use a specially crafted domain name that passes the hostname check yet…

Deno is a JavaScript, TypeScript, and WebAssembly runtime. From 2.7.0 to 2.7.1, A command injection vulnerability exists in Deno's node:child_process polyfill (shell: true mode) that bypasses the fix for CVE-2026-27190. The two-stage argument sanitization in…

Deno is a JavaScript, TypeScript, and WebAssembly runtime. Prior to 2.6.8, a command injection vulnerability exists in Deno's node:child_process implementation. This vulnerability is fixed in 2.6.8.

Deno is a JavaScript, TypeScript, and WebAssembly runtime. Before 2.5.6, a prior patch aimed to block spawning Windows batch/shell files by returning an error when a spawned path’s extension matched .bat or .cmd. That check performs a case-sensitive comparison against…

Deno is a JavaScript, TypeScript, and WebAssembly runtime. Before 2.6.0, node:crypto doesn't finalize cipher. The vulnerability allows an attacker to have infinite encryptions. This can lead to naive attempts at brute forcing, as well as more refined attacks with the goal to…

Deno is a JavaScript, TypeScript, and WebAssembly runtime. Versions prior to 2.5.3 and 2.2.15 are vulnerable to Command Line Injection attacks on Windows when batch files are executed. In Windows, ``CreateProcess()`` always implicitly spawns ``cmd.exe`` if a batch file (.bat,…

Deno is a JavaScript, TypeScript, and WebAssembly runtime. In versions prior to 2.5.3 and 2.2.15, `Deno.FsFile.prototype.stat` and `Deno.FsFile.prototype.statSync` are not limited by the permission model check `--deny-read=./`. It's possible to retrieve stats from files that the…

Deno is a JavaScript, TypeScript, and WebAssembly runtime. In versions prior to 2.5.3 and 2.2.15, `Deno.FsFile.prototype.utime` and `Deno.FsFile.prototype.utimeSync` are not limited by the permission model check `--deny-write=./`. It's possible to change to change the access…

Deno is a JavaScript, TypeScript, and WebAssembly runtime. Starting in version 2.2.0 and prior to versions 2.2.5, it is possible to bypass Deno's permission read/write db permission check by using `ATTACH DATABASE` statement. Version 2.2.5 contains a patch for the issue.

Deno is a JavaScript, TypeScript, and WebAssembly runtime. Prior to versions 2.1.13 and 2.2.13, the `Deno.env.toObject` method ignores any variables listed in the `--deny-env` option of the `deno run` command. When looking at the documentation of the `--deny-env` option this…

Deno is a JavaScript, TypeScript, and WebAssembly runtime. Starting in version 1.41.3 and prior to versions 2.1.13, 2.2.13, and 2.3.2, `deno run --allow-read --deny-read main.ts` results in allowed, even though 'deny' should be stronger. The result is the same with all global…

Deno is a JavaScript, TypeScript, and WebAssembly runtime. Versions 1.46.0 through 2.1.6 have an issue that affects AES-256-GCM and AES-128-GCM in Deno in which the authentication tag is not being validated. This means tampered ciphertexts or incorrect keys might not be…

An issue in `.npmrc` support in Deno 1.44.0 was discovered where Deno would send `.npmrc` credentials for the scope to the tarball URL when the registry provided URLs for a tarball on a different domain. All users relying on .npmrc are potentially affected by this vulnerability…

Deno is a JavaScript, TypeScript, and WebAssembly runtime with secure defaults. The Deno sandbox may be unexpectedly weakened by allowing file read/write access to privileged files in various locations on Unix and Windows platforms. For example, reading `/proc/self/environ` may…

Deno is a JavaScript, TypeScript, and WebAssembly runtime with secure defaults. By using ANSI escape sequences and a race between `libc::tcflush(0, libc::TCIFLUSH)` and reading standard input, it's possible to manipulate the permission prompt and force it to allow an unsafe…

Deno is a JavaScript, TypeScript, and WebAssembly runtime with secure defaults. Starting in version 1.32.1 and prior to version 1.41.0 of the deno library, maliciously crafted permission request can show the spoofed permission prompt by inserting a broken ANSI escape sequence…

Deno is a JavaScript, TypeScript, and WebAssembly runtime. Starting in version 1.35.1 and prior to version 1.36.3, a vulnerability in Deno's Node.js compatibility runtime allows for cross-session data contamination during simultaneous asynchronous reads from Node.js streams…

Deno is a JavaScript, TypeScript, and WebAssembly runtime. Starting in version 1.36.2 and prior to version 1.40.3, use of inherently unsafe `*const c_void` and `ExternalPointer` leads to use-after-free access of the underlying structure, resulting in arbitrary code execution.…

Deno is a JavaScript, TypeScript, and WebAssembly runtime. In version 1.39.0, use of raw file descriptors in `op_node_ipc_pipe()` leads to premature close of arbitrary file descriptors, allowing standard input to be re-opened as a different resource resulting in permission…

Deno is a JavaScript, TypeScript, and WebAssembly runtime. Starting in version 1.8.0 and prior to version 1.40.4, Deno improperly checks that an import specifier's hostname is equal to or a child of a token's hostname, which can cause tokens to be sent to servers they shouldn't…

Deno is a JavaScript, TypeScript, and WebAssembly runtime with secure defaults. Insufficient validation of parameters in `Deno.makeTemp*` APIs would allow for creation of files outside of the allowed directories. This may allow the user to overwrite important files on the system…

Deno is a runtime for JavaScript and TypeScript. In deno 1.34.0 and deno_runtime 0.114.0, outbound HTTP requests made using the built-in `node:http` or `node:https` modules are incorrectly not checked against the network permission allow list (`--allow-net`). Dependencies…

Deno is a simple, modern and secure runtime for JavaScript and TypeScript that uses V8 and is built in Rust. Arbitrary program names without any ANSI filtering allows any malicious program to clear the first 2 lines of a `op_spawn_child` or `op_kill` prompt and replace it with…

Deno is a runtime for JavaScript and TypeScript that uses V8 and is built in Rust. Resizable ArrayBuffers passed to asynchronous functions that are shrunk during the asynchronous operation could result in an out-of-bound read/write. It is unlikely that this has been exploited in…

Versions of the package deno before 1.31.0 are vulnerable to Regular Expression Denial of Service (ReDoS) due to the upgradeWebSocket function, which contains regexes in the form of /s*,s*/, used for splitting the Connection/Upgrade header. A specially crafted Connection/Upgrade…

Deno is a runtime for JavaScript and TypeScript that uses V8 and is built in Rust. Multi-threaded programs were able to spoof interactive permission prompt by rewriting the prompt to suggest that program is waiting on user confirmation to unrelated action. A malicious program…

Deno <=1.14.0 file sandbox does not handle symbolic links correctly. When running Deno with specific write access, the Deno.symlink method can be used to gain access to any directory.

Deno is a runtime for JavaScript and TypeScript. The versions of Deno between release 1.18.0 and 1.20.2 (inclusive) are vulnerable to an attack where a malicious actor controlling the code executed in a Deno runtime could bypass all permission checks and execute arbitrary shell…

Deno Standard Modules before 0.107.0 allows Code Injection via an untrusted YAML file in certain configurations.

Deno is a runtime for JavaScript and TypeScript that uses V8 and is built in Rust. In Deno versions 1.5.0 to 1.10.1, modules that are dynamically imported through `import()` or `new Worker` might have been able to bypass network and file system permission checks when statically…