PYSEC-2026-2627 MCP Run Python Deno Sandbox Misconfiguration Allows SSRF Attacks via Localhost Access

Impact Server-Side Request Forgery SSRF: A security vulnerability exists in the mcp-run-python tool specifically within the Pydantic-AI integration due to an overly permissive Deno sandbox configuration. The tool configures the Deno runtime—which is intended to isolate the execution of untrusted...

CVE-2026-48504 vulnerabilities

Vulnerabilities for packages: wasmcloud, linkerd2-proxy, mountpoint-s3, deno, parseable...

GHSA-W9WP-H8WV-79JX vulnerabilities

Vulnerabilities for packages: wasmcloud, linkerd2-proxy, mountpoint-s3, deno, parseable...

GHSA-W9WP-H8WV-79JX vulnerabilities

Vulnerabilities for packages: parseable, deno, wasmcloud, linkerd2-proxy, mountpoint-s3...

CVE-2026-48504 vulnerabilities

Vulnerabilities for packages: parseable, deno, wasmcloud, linkerd2-proxy, mountpoint-s3...

JLSEC-2026-655 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...

JLSEC-2026-656 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 %...

JLSEC-2026-654 Deno's TLS retry copies stale upgrade hook, risking plaintext traffic

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 stale TLS upgrade hook tha...

JLSEC-2026-658 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...

CVE-2026-55517

Deno is a JavaScript, TypeScript, and WebAssembly runtime. Prior to 2.7.5, 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...

CVE-2026-49860

Deno is a JavaScript, TypeScript, and WebAssembly runtime. Prior to 2.8.1, 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...

CVE-2026-49983

Deno is a JavaScript, TypeScript, and WebAssembly runtime. Prior to 2.8.1, 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...

CVE-2026-49402

Deno is a JavaScript, TypeScript, and WebAssembly runtime. Prior to 2.7.10, 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.e...

CVE-2026-49411

Deno is a JavaScript, TypeScript, and WebAssembly runtime. Prior to 2.8.0, the Node.js compatibility TCP path checked the permission against the original hostname string before resolution and then did not re-check after resolution. A caller could therefore pass a numeric alias of an IP address fo...

CVE-2026-49401

Deno is a JavaScript, TypeScript, and WebAssembly runtime. Prior to 2.7.14, 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...

CVE-2026-49859

Deno is a JavaScript, TypeScript, and WebAssembly runtime. Prior to 2.8.1, 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...

CVE-2026-49440

Deno is a JavaScript, TypeScript, and WebAssembly runtime. Prior to 2.8.1, 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 ...

CVE-2026-49406

Deno is a JavaScript, TypeScript, and WebAssembly runtime. Prior to 2.7.12, 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...

CVE-2026-44726

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...

CVE-2026-55517 Deno: Denial of service via non-ASCII bytes in WebSocket response headers

Deno is a JavaScript, TypeScript, and WebAssembly runtime. Prior to 2.7.5, 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...