CVE-2026-21715: nodejs node vulnerability
Advisory generated from the CVE record, CISA, Exploit Observer and VEDAS: what it is, whether it is exploited, who is affected, and how to fix and detect it.
Generated by VEDAS. Scores as of 2026-11-08 00:03 UTC. Rebuilt every few hours from cve-scores, CISA KEV and vedas-signatures. How this works and its limits.
What it is
A flaw in Node.js Permission Model filesystem enforcement leaves `fs.realpathSync.native()` without the required read permission checks, while all comparable filesystem functions correctly enforce them. As a result, code running under `--permission` with restricted `--allow-fs-read` can still use `fs.realpathSync.native()` to check file existence, resolve symlink targets, and enumerate filesystem paths outside of permitted directories. This vulnerability affects **20.x, 22.x, 24.x, and 25.x** processes using the Permission Model where `--allow-fs-read` is intentionally restricted.
Description quoted from the CVE record (assigned by hackerone, published 2026-03-30).
Weakness: CWE-732 Incorrect Permission Assignment for Critical Resource
How it can be exploited
Exploitable with local access with low attack complexity needing low privileges and no user interaction. Impact: confidentiality low, integrity none, availability none. CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N
CISA assessment (SSVC): CISA has no evidence of exploitation. Automatable: no. Technical impact: partial.
Public exploit evidence (Exploit Observer)
Exploit Observer has no public exploit code naming this CVE. Check Exploit Observer for anything new.
Live scores
- EPSS
- 0.002
low predicted chance of attack - VEDAS
- 0.973
strong exploit evidence - On CISA KEV
- Not listed
- Detection rule
- No public rule yet
Who is affected
| Product | Affected | Not affected |
|---|---|---|
| nodejs node | from 20.20.1 up to and including 20.20.1 from 22.22.1 up to and including 22.22.1 from 24.14.0 up to and including 24.14.0 from 25.8.1 up to and including 25.8.1 from 4.0 before 4.* from 5.0 before 5.* from 6.0 before 6.* from 7.0 before 7.* and 12 more ranges | Not stated |
Version ranges exactly as the CVE record states them. “Before X” means X is the first fixed version.
How to fix it
Fixed versions stated in the CVE record: 4.*, 5.*, 6.*, 7.*, 8.*, 9.*, 10.*, 11.*, 12.*, 13.*, 14.*, 15.* and others.
How to detect it
There is no open VEDAS detection rule for this bug yet. It is listed on the detection gaps page if CISA has confirmed attacks.
Advisories on this CVE
- Node.js October 2026 security release: Brotli RCE now exploited, plus TLS hostname bypasses (full advisory)
References
Other references
Other databases
Where this comes from
This advisory is generated automatically by VEDAS from: CVE.org record, cve-scores (EPSS and VEDAS), Exploit Observer. Text in quotes is reproduced from the source; everything else is a fixed template filled with source fields. Nothing here is written by a language model. Check the vendor advisory before acting, and read how VEDAS and Exploit Observer work, and their limits.
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