GHSA-X2QC-CMH9-F4HF Deno: Denial of service via non-ASCII bytes in WebSocket response headers

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 bytes were always printable ASCI...

PT-2026-50601

Name of the Vulnerable Software and Affected Versions Deno versions prior to 2.7.5 Description A Deno program opening a client WebSocket connection can be crashed by a remote server. During the WebSocket handshake response, Deno parsed the 'Sec-WebSocket-Protocol' and 'Sec-WebSocket-Extensions'...

Deno: Permission Bypass via Unicode Normalization Mismatch on macOS (APFS)

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 filesystem treats different...

GHSA-8XPQ-CJCF-3WH9 Deno: Permission Bypass via Unicode Normalization Mismatch on macOS (APFS)

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 filesystem treats different...

GHSA-968W-XFQW-VP9Q Deno: BYONM module resolution allows `package.json` main path traversal to bypass `--allow-read` restrictions

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 nodemodules// directory. A malicious package.json whose main field contained .. segments was able to resolve to an arbitrary path on disk,...

GHSA-V8FW-85R8-5M23 Deno: Node TCPWrap numeric hostname aliases bypass --deny-net resolved-IP deny checks

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 attempt to reach loopback,...

GHSA-9XG4-QHM4-G43W Deno: Miller-Rabin Primality Test Allows Zero Rounds

Summary node:crypto.checkPrimecandidate, options, callback and crypto.checkPrimeSynccandidate, 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 division by the primes up to 17,863. Any...

GHSA-7XH3-MHG9-JCW8 Deno: Command Injection via spawnSync & spawn on Windows

Summary Deno's node:childprocess 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 &, |, , ^, !, , , and did not neutralize %...

Deno: process.loadEnvFile() bypasses env permission checks and mutates process.env with only read access

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. process.loadEnvFile the Node-compatible...

GHSA-4C8G-JVCX-V4HV Deno: process.loadEnvFile() bypasses env permission checks and mutates process.env with only read access

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. process.loadEnvFile the Node-compatible...

Deno: WebSocket API sandbox bypass via missing post-DNS check

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 check yet resolves to a...

GHSA-83PC-3RW9-QPWJ Deno: WebSocket API sandbox bypass via missing post-DNS check

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 check yet resolves to a...

Deno: `fetch()` API sandbox bypass via missing DNS resolution check

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 resolves to a denied IP,...

GHSA-CPGJ-F7G3-2PP2 Deno: `fetch()` API sandbox bypass via missing DNS resolution check

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 resolves to a denied IP,...

PT-2026-50146

Name of the Vulnerable Software and Affected Versions Deno versions prior to 2.7.10 Description In the node:child process implementation on Windows, the escapeShellArg helper function fails to properly quote arguments containing cmd.exe metacharacters such as &, |, , ^, !, , and and does not...

PT-2026-50155

Name of the Vulnerable Software and Affected Versions Deno versions prior to 2.8.1 Description Environment access is managed by the env permission, which can be restricted via --deny-env or an allowlist using --allow-env=FOO,BAR. The process.loadEnvFile function, a Node-compatible API for loading...

PT-2026-50148

Name of the Vulnerable Software and Affected Versions Deno versions prior to 2.8.0 Description The Node.js compatibility TCP path fails to re-verify network permissions after hostname resolution. While the network permission model is intended to apply rules to the resolved IP address, affected...

PT-2026-50145

Name of the Vulnerable Software and Affected Versions Deno versions prior to 2.7.14 Description Deno's permission system on macOS enforces filesystem and execution restrictions by comparing requested paths against those supplied to --deny-read, --deny-write, --deny-run, or --deny-ffi. The...

PT-2026-50153

Name of the Vulnerable Software and Affected Versions Deno versions prior to 2.8.1 Description When the fetch function is called, the runtime validates the destination hostname against --deny-net rules but fails to re-verify the IP addresses that the hostname resolves to. This allows an...

Withdrawn Advisory: esbuild: Missing binary integrity verification in Deno module enables remote code execution via NPM_CONFIG_REGISTRY

Withdrawn Advisory This advisory has been withdrawn because the affected package was incorrectly identified and the actual affected package is not in a supported ecosystem. This link is maintained to preserve external references. Original Description Summary The esbuild Deno module lib/deno/mod.t...