Critical 10.0Published Feb 6, 2026

CVE-2026-25641SandboxJS has a sandbox escape via TOCTOU bug on keys in property accesses

Updated under an hour ago (Oct 26, 2026, 5:10 AM ET)

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No exploitation reported and no EPSS estimate yet.

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Every CVE for nyariv SandboxJS

Exploited in the last 30 days

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 (v3.1, CNA)CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
Weakness (CWE): CWE-367
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: GitHub_M
NVD analysis: Analyzed
Record last updated: Feb 6, 2026
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

nyariv SandboxJS nyariv:sandboxjs (from the name)	before 0.8.29	CNA record
nyariv sandboxjs nyariv:sandboxjs	before 0.8.29	NVD

References

https://github.com/nyariv/SandboxJS/security/advisories/GHSA-7x3h-rm86-3342x-refsource-confirm, exploit, vendor-advisory
https://github.com/nyariv/SandboxJS/commit/67cb186c41c78c51464f70405504e8ef0a6e43c3x-refsource-misc, patch
https://github.com/nyariv/SandboxJS/blob/6103d7147c4666fe48cfda58a4d5f37005b43754/src/executor.ts#L304-L304x-refsource-misc, product

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.