CVE-2026-49401 Deno Permission Bypass via Unicode Normalization Mismatch on macOS (APFS)

What is CVE-2026-49401?

CVE-2026-49401 is a high-severity vulnerability in denoland deno, published on 23 Jun 2026. It can only be exploited from the same machine or local network, with no action from the victim.

Official description

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 at the raw-byte level while the APFS filesystem treats different Unicode spellings of the same name as the same file. That means a program could reach a denied path by spelling it differently than the deny rule. This vulnerability is fixed in 2.7.14.

Weakness: CWE-41, CWE-176

Which versions are affected by CVE-2026-49401?

2 open source packages ship an affected version, including deno. It affects 1 product.

Products include Deno Deno.

How do I fix CVE-2026-49401?

Upgrade deno to 2.7.14 or later.

Is CVE-2026-49401 being exploited?

There is no known exploitation of CVE-2026-49401 in the wild and no public exploit code.

Other vulnerabilities in denoland deno

• CVE-2023-28445 Deno improperly handles resizable ArrayBuffer Critical 10.0
• CVE-2022-24783 Sandbox bypass leading to arbitrary code execution in Deno Critical 10.0
• CVE-2021-32619 Static imports inside dynamically imported modules do not adhere to permission checks Critical 9.8
• CVE-2026-22863 Deno node:crypto doesn't finalize cipher Critical 9.2
• CVE-2024-27936 Deno interactive permission prompt spoofing via improper ANSI stripping High 8.8

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as GHSA-8xpq-cjcf-3wh9, JLSEC-2026-655.