CVE-2026-21716

The record

An incomplete fix for CVE-2024-36137 leaves `FileHandle.chmod()` and `FileHandle.chown()` in the promises API without the required permission checks, while their callback-based equivalents (`fs.fchmod()`, `fs.fchown()`) were correctly patched. As a result, code running under `--permission` with restricted `--allow-fs-write` can still use promise-based `FileHandle` methods to modify file permissions and ownership on already-open file descriptors, bypassing the intended write restrictions. This vulnerability affects **20.x, 22.x, 24.x, and 25.x** processes using the Permission Model where `--allow-fs-write` is intentionally restricted.

Affected packages

Related vulnerabilities

• CVE-2026-48935 A flaw in Node.js Permission API can cause a file metadata to be modified even on a path… Also affects nodejs22
• CVE-2026-48618 A flaw in Node.js TLS hostname handling can cause Node.js unicode dot separator handling… Also affects nodejs22
• CVE-2026-48930 A flaw in Node.js TLS hostname handling can cause Embedded-nul hostnames can lead to… Also affects nodejs22
• CVE-2026-48615 A flaw in Node.js proxy tunnel error handling could expose proxy credentials in… Also affects nodejs22
• CVE-2026-48619 A flaw in Node.js HTTP/2 client allows a server to send an unlimited number of ORIGIN… Also affects nodejs22
• CVE-2026-48933 A flaw in Node.js WebCrypto implementation can crash the process if the input of… Also affects nodejs22
• CVE-2026-48928 A inconsistency in Node.js hostname matching can cause a trust-policy bypass in… Also affects nodejs22
• CVE-2026-48934 A flaw in Node.js TLS host verification can cause an attacker to bypass certification… Also affects nodejs22