Vulnerability Description
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.
CVSS Score
CRITICAL
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Nyariv | Sandboxjs | < 0.8.29 |
Related Weaknesses (CWE)
References
- https://github.com/nyariv/SandboxJS/blob/6103d7147c4666fe48cfda58a4d5f37005b4375Product
- https://github.com/nyariv/SandboxJS/commit/67cb186c41c78c51464f70405504e8ef0a6e4Patch
- https://github.com/nyariv/SandboxJS/security/advisories/GHSA-7x3h-rm86-3342ExploitVendor Advisory
- https://github.com/nyariv/SandboxJS/security/advisories/GHSA-7x3h-rm86-3342ExploitVendor Advisory
FAQ
What is CVE-2026-25641?
CVE-2026-25641 is a vulnerability with a CVSS score of 10.0 (CRITICAL). 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 acces...
How severe is CVE-2026-25641?
CVE-2026-25641 has been rated CRITICAL with a CVSS base score of 10.0/10. This is considered a critical vulnerability requiring immediate attention.
Is there a patch for CVE-2026-25641?
Check the references section above for vendor advisories and patch information. Affected products include: Nyariv Sandboxjs.