CVE-2026-25641

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 v3 10.0 CRITICAL

10.0^/10

CVSS v3 : CRITICAL

Vector :

Exploitability : 3.9 / Impact : 6.0

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction NONE

Confidentiality Impact HIGH

Integrity Impact HIGH

Availability Impact HIGH

Scope CHANGED

References

Link	Resource
https://github.com/nyariv/SandboxJS/blob/6103d7147c4666fe48cfda58a4d5f37005b43754/src/executor.ts#L304-L304	Product
https://github.com/nyariv/SandboxJS/commit/67cb186c41c78c51464f70405504e8ef0a6e43c3	Patch
https://github.com/nyariv/SandboxJS/security/advisories/GHSA-7x3h-rm86-3342	Exploit Vendor Advisory
https://github.com/nyariv/SandboxJS/security/advisories/GHSA-7x3h-rm86-3342	Exploit Vendor Advisory

Configurations

Configuration 1 (hide)

cpe:2.3:a:nyariv:sandboxjs:*:*:*:*:*:node.js:*:*

History

No history.

Information

Published : 2026-02-06 20:16

Updated : 2026-02-18 14:01

NVD link : CVE-2026-25641

Mitre link : CVE-2026-25641

CVE.ORG link : CVE-2026-25641

JSON object : View

Products Affected

nyariv

sandboxjs

CWE

CWE-367

Time-of-check Time-of-use (TOCTOU) Race Condition

{"id": "CVE-2026-25641", "cveTags": [], "metrics": {"cvssMetricV31": [{"type": "Secondary", "source": "security-advisories@github.com", "cvssData": {"scope": "CHANGED", "version": "3.1", "baseScore": 10.0, "attackVector": "NETWORK", "baseSeverity": "CRITICAL", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H", "integrityImpact": "HIGH", "userInteraction": "NONE", "attackComplexity": "LOW", "availabilityImpact": "HIGH", "privilegesRequired": "NONE", "confidentialityImpact": "HIGH"}, "impactScore": 6.0, "exploitabilityScore": 3.9}, {"type": "Primary", "source": "nvd@nist.gov", "cvssData": {"scope": "CHANGED", "version": "3.1", "baseScore": 9.0, "attackVector": "NETWORK", "baseSeverity": "CRITICAL", "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H", "integrityImpact": "HIGH", "userInteraction": "NONE", "attackComplexity": "HIGH", "availabilityImpact": "HIGH", "privilegesRequired": "NONE", "confidentialityImpact": "HIGH"}, "impactScore": 6.0, "exploitabilityScore": 2.2}]}, "published": "2026-02-06T20:16:11.263", "references": [{"url": "https://github.com/nyariv/SandboxJS/blob/6103d7147c4666fe48cfda58a4d5f37005b43754/src/executor.ts#L304-L304", "tags": ["Product"], "source": "security-advisories@github.com"}, {"url": "https://github.com/nyariv/SandboxJS/commit/67cb186c41c78c51464f70405504e8ef0a6e43c3", "tags": ["Patch"], "source": "security-advisories@github.com"}, {"url": "https://github.com/nyariv/SandboxJS/security/advisories/GHSA-7x3h-rm86-3342", "tags": ["Exploit", "Vendor Advisory"], "source": "security-advisories@github.com"}, {"url": "https://github.com/nyariv/SandboxJS/security/advisories/GHSA-7x3h-rm86-3342", "tags": ["Exploit", "Vendor Advisory"], "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0"}], "vulnStatus": "Analyzed", "weaknesses": [{"type": "Secondary", "source": "security-advisories@github.com", "description": [{"lang": "en", "value": "CWE-367"}]}], "descriptions": [{"lang": "en", "value": "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."}, {"lang": "es", "value": "SandboxJS es una librer\u00eda de sandboxing de JavaScript. Antes de 0.8.29, existe una vulnerabilidad de escape de sandbox debido a una discrepancia entre la clave sobre la que se realiza la validaci\u00f3n y la clave utilizada para acceder a las propiedades. Aunque la clave utilizada en los accesos a propiedades est\u00e1 anotada como string, esto nunca se aplica. As\u00ed, los atacantes pueden pasar objetos maliciosos que se convierten a diferentes valores de string cuando se usan, por ejemplo, uno para el momento en que la clave se sanea usando hasOwnProperty(key) y uno diferente para cuando la clave se usa para el acceso real a la propiedad. Esta vulnerabilidad est\u00e1 corregida en 0.8.29."}], "lastModified": "2026-02-18T14:01:02.337", "configurations": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:a:nyariv:sandboxjs:*:*:*:*:*:node.js:*:*", "vulnerable": true, "matchCriteriaId": "5822AD4C-2C8E-4196-9149-A626F0572E05", "versionEndExcluding": "0.8.29"}], "operator": "OR"}]}], "sourceIdentifier": "security-advisories@github.com"}