A flaw in Node.js Permission Model filesystem enforcement leaves `fs.realpathSync()` without the required read permission checks.
- Published
- Last modified
- Where the record stands: published, rejected by its publisher, or superseded by another id.What do these mean? →
- published
- Whether CISA lists it in its Known Exploited Vulnerabilities catalog: proof that attackers are using it.What do these mean? →
- Not listed in CISA KEV
- Whether working attack code is public (Exploit-DB, Metasploit, Nuclei or GitHub). Public code makes attacks easier.What do these mean? →
- None on Exploit-DB, Metasploit or GitHub
Summary
Node.js is affected, specifically its Permission Model feature (used with the `--permission` flag). Code running under restricted filesystem read permissions can still use `fs.realpathSync()` to check whether files exist, resolve symlink targets, and list paths outside the directories it is allowed to access, which weakens the sandbox's intended isolation.
Summarized by anthropic/claude-haiku-5.5. Verify details against the original sources.
Read the original description
A flaw in Node.js Permission Model filesystem enforcement leaves `fs.realpathSync()` without the required read permission checks. This is an incomplete fix of CVE-2026-21715, which only covered `fs.realpathSync.native()`. As a result, code running under `--permission` with restricted `--allow-fs-read` can still use `fs.realpathSync()` to check file existence, resolve symlink targets, and enumerate filesystem paths outside of permitted directories. This vulnerability affects Node.js 26.x, 24.x, and 22.x.
Timeline
- CVE published
- First seen by cve.now
Affected versions
- nodejs node
From 22.23.3 · through 22.23.3; From 24.22.0 · through 24.22.0; From 26.12.0 · through 26.12.0