Vulnerabilities

Deno is a JavaScript, TypeScript, and WebAssembly runtime. From 2.0.0 until 2.7.8, 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 stale TLS upgrade hook that was bound to the original, failed handle. As a result, the replacement TCP connection was never upgraded to TLS, and any data the application wrote before the secureConnect event travelled over the network unencrypted. A network attacker positioned to cause the initial connection attempt to fail (for example, by dropping IPv6 traffic on a dual-stack host) could deterministically trigger the fallback path and observe or tamper with traffic that the application believed was TLS-protected. This vulnerability is fixed in 2.7.8.

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 transformDenoShellCommand (ext/node/polyfills/internal/child_process.ts) has a priority bug: when an argument contains a $VAR pattern, it is wrapped in double quotes (L1290) instead of single quotes. Double quotes in POSIX sh do not suppress backtick command substitution, allowing injected commands to execute. An attacker who controls arguments passed to spawnSync or spawn with shell: true can execute arbitrary OS commands, bypassing Deno's permission system. This vulnerability is fixed in 2.7.2.

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 lowercase literals and therefore can be bypassed when the extension uses alternate casing (for example .BAT, .Bat, etc.). This vulnerability is fixed in 2.5.6.

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, .cmd, etc.) is being executed even if the application does not specify it via the command line. This makes Deno vulnerable to a command injection attack on Windows. Versions 2.5.3 and 2.2.15 fix the issue.

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. 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 detected, which breaks the guarantees expected from AES-GCM. Older versions of Deno correctly threw errors in such cases, as does Node.js. Without authentication tag verification, AES-GCM degrades to essentially CTR mode, removing integrity protection. Authenticated data set with set_aad is also affected, as it is incorporated into the GCM hash (ghash) but this too is not validated, rendering AAD checks ineffective. Version 2.1.7 includes a patch that addresses this issue.

mmudb v1.9.3 was discovered to use the HTTP protocol in the ShowMetricsRaw and ShowMetricsAsText functions, possibly allowing attackers to intercept communications via a man-in-the-middle attack.

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 if their private registry references tarball URLs at a different domain. This includes usage of deno install subcommand, auto-install for npm: specifiers and LSP usage. It is recommended to upgrade to Deno 1.44.1 and if your private registry ever serves tarballs at a different domain to rotate your registry credentials.

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 provide access equivalent to `--allow-env`, and writing `/proc/self/mem` may provide access equivalent to `--allow-all`. Users who grant read and write access to the entire filesystem may not realize that these access to these files may have additional, unintended consequences. The documentation did not reflect that this practice should be undertaken to increase the strength of the security sandbox. Users who run code with `--allow-read` or `--allow-write` may unexpectedly end up granting additional permissions via file-system operations. Deno 1.43 and above require explicit `--allow-all` access to read or write `/etc`, `/dev` on unix platform (as well as `/proc` and `/sys` on linux platforms), and any path starting with `\\` on Windows.

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 action regardless of the user input. Some ANSI escape sequences act as a info request to the master terminal emulator and the terminal emulator sends back the reply in the PTY channel. standard streams also use this channel to send and get data. For example the `\033[6n` sequence requests the current cursor position. These sequences allow us to append data to the standard input of Deno. This vulnerability allows an attacker to bypass Deno permission policy. This vulnerability is fixed in 1.42.2.

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 prompt bypass. Node child_process IPC relies on the JS side to pass the raw IPC file descriptor to `op_node_ipc_pipe()`, which returns a `IpcJsonStreamResource` ID associated with the file descriptor. On closing the resource, the raw file descriptor is closed together. Use of raw file descriptors in `op_node_ipc_pipe()` leads to premature close of arbitrary file descriptors. This allow standard input (fd 0) to be closed and re-opened for a different resource, which allows a silent permission prompt bypass. This is exploitable by an attacker controlling the code executed inside a Deno runtime to obtain arbitrary code execution on the host machine regardless of permissions. This bug is known to be exploitable. There is a working exploit that achieves arbitrary code execution by bypassing prompts from zero permissions, additionally abusing the fact that Cache API lacks filesystem permission checks. The attack can be conducted silently as stderr can also be closed, suppressing all prompt outputs. Version 1.39.1 fixes the bug.

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 that may affect other systems. A user may provide a prefix or suffix to a `Deno.makeTemp*` API containing path traversal characters. This is fixed in Deno 1.41.1.

The Site Notes WordPress plugin through 2.0.0 does not have CSRF checks in some of its functionalities, which could allow attackers to make logged in users perform unwanted actions, such as deleting administration notes, via CSRF attacks

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 relying on these built-in modules are subject to the vulnerability too. Users of Deno versions prior to 1.34.0 are unaffected. Deno Deploy users are unaffected. This problem has been patched in Deno v1.34.1 and deno_runtime 0.114.1 and all users are recommended to update to this version. No workaround is available for this issue.

The Denosaurs emoji package provides emojis for dinosaurs. Starting in version 0.1.0 and prior to version 0.3.0, the reTrimSpace regex has 2nd degree polynomial inefficiency, leading to a delayed response given a big payload. The issue has been patched in 0.3.0. As a workaround, avoid using the `replace`, `unemojify`, or `strip` functions.

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 the wild, as the only version affected is Deno 1.32.0. Deno Deploy users are not affected. The problem has been resolved by disabling resizable ArrayBuffers temporarily in Deno 1.32.1. Deno 1.32.2 will re-enable resizable ArrayBuffers with a proper fix. As a workaround, run with `--v8-flags=--no-harmony-rab-gsab` to disable resizable ArrayBuffers.

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 header can be used to significantly slow down a web socket server.

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 could clear the terminal screen after permission prompt was shown and write a generic message. This situation impacts users who use Web Worker API and relied on interactive permission prompt. The reproduction is very timing sensitive and can’t be reliably reproduced on every try. This problem can not be exploited on systems that do not attach an interactive prompt (for example headless servers). The problem has been fixed in Deno v1.29.3; it is recommended all users update to this version. Users are advised to upgrade. Users unable to upgrade may run with --no-prompt flag to disable interactive permission prompts.

immudb is a database with built-in cryptographic proof and verification. In versions prior to 1.4.1, a malicious immudb server can provide a falsified proof that will be accepted by the client SDK signing a falsified transaction replacing the genuine one. This situation can not be triggered by a genuine immudb server and requires the client to perform a specific list of verified operations resulting in acceptance of an invalid state value. This vulnerability only affects immudb client SDKs, the immudb server itself is not affected by this vulnerability. This issue has been patched in version 1.4.1.

immudb is a database with built-in cryptographic proof and verification. immudb client SDKs use server's UUID to distinguish between different server instance so that the client can connect to different immudb instances and keep the state for multiple servers. SDK does not validate this uuid and can accept any value reported by the server. A malicious server can change the reported UUID tricking the client to treat it as a different server thus accepting a state completely irrelevant to the one previously retrieved from the server. This issue has been patched in version 1.4.1. As a workaround, when initializing an immudb client object a custom state handler can be used to store the state. Providing custom implementation that ignores the server UUID can be used to ensure that even if the server changes the UUID, client will still consider it to be the same server.

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 code. This vulnerability does not affect users of Deno Deploy. The vulnerability has been patched in Deno 1.20.3. There is no workaround. All users are recommended to upgrade to 1.20.3 immediately.

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 importing other modules. The vulnerability has been patched in Deno release 1.10.2.