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Microsoft Security Response CenterCVE-2026-21716

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.

Mariner

3.3CVSS out of 10Low severity
Scope

What the vendor says is affected

  • azl3 nodejs24 24.13.0-3 on Azure Linux 3.0
  • azl3 nodejs 20.14.0-14 on Azure Linux 3.0

Versions the vendor lists as fixed

  • 24.14.1-1
  • 20.14.0-15
Next step

What the vendor recommends

CBL-Mariner Releases

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Timeline

When this advisory changed

  1. Published by Microsoft Security Response Center

    The publication date reported by the vendor.

  2. Updated by Microsoft Security Response Center

    The vendor changed the advisory after it was first published.

  3. Added to SecurityAlert

    We collected the advisory from the official source.

  4. Confirmed at the source

    Our collector saw this advisory during a later source check.

Vulnerabilities

CVEs named in this advisory