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CVE-2026-25641GHSA-7X3H-RM86-3342

SandboxJS has a sandbox escape via TOCTOU bug on keys in property accesses

Published
Last modified
published
Not listed in CISA KEV
Fix
Fixed in 0.8.29
None on Exploit-DB, Metasploit or GitHub
  • Exploitation: poc
  • Automatable: yes
  • Technical impact: total

Summary

SandboxJS is a JavaScript sandboxing library. Prior to 0.8.29, there is a sandbox escape vulnerability due to a mismatch between the key on which the validation is performed and the key used for accessing properties. Even though the key used in property accesses is annotated as string, this is never enforced. So, attackers can pass malicious objects that coerce to different string values when used, e.g., one for the time the key is sanitized using hasOwnProperty(key) and a different one for when the key is used for the actual property access. This vulnerability is fixed in 0.8.29.

Timeline

  1. CVE published
  2. CISA SSVC assessment

    Exploitation: poc · Automatable: yes · Technical impact: total

  3. Record last updated

Affected versions

  • nyariv SandboxJS

    fixed in 0.8.29

  • @nyariv/sandboxjsnpm

    fixed in 0.8.29

References 3

GitHub · nyariv/SandboxJS