CVE-2026-25641
CVE-2026-25641 · SandboxJS has a sandbox escape via TOCTOU bug on keys in property accesses
This page contains facts from public vulnerability sources. Check the original advisory before updating.
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 10.0 · Critical · EPSS 0.5% · Fix available
- Published
- Updated
Stack: node
Affected products and versions
sandboxjs
- Versions
- < 0.8.29: Affected
No fix published
@nyariv/sandboxjs npm
- Affected ranges
- SEMVER: < 0.8.29
Update to 0.8.29
Original sources
- https://github.com/nyariv/SandboxJS/security/advisories/GHSA-7x3h-rm86-3342
- https://github.com/nyariv/SandboxJS/commit/67cb186c41c78c51464f70405504e8ef0a6e43c3
- https://github.com/nyariv/SandboxJS/blob/6103d7147c4666fe48cfda58a4d5f37005b43754/src/executor.ts#L304-L304
- https://nvd.nist.gov/vuln/detail/CVE-2026-25641