CVE-2026-43898: CWE-94: Improper Control of Generation of Code ('Code Injection') in nyariv SandboxJS
SandboxJS is a JavaScript sandboxing library. Prior to 0.9.6, sandbox-defined functions expose Function.caller, allowing sandboxed code to recover the internal LispType.Call runtime callback. That callback can then be invoked with attacker-controlled fake context and obj values to extract blocked host statics, recover the real host Function constructor, and execute arbitrary host JavaScript. This vulnerability is fixed in 0.9.6.
AI Analysis
Technical Summary
SandboxJS versions before 0.9.6 suffer from a code injection vulnerability (CWE-94) due to improper control over the generation of code. Specifically, sandbox-defined functions expose Function.caller, which allows sandboxed code to access the internal LispType.Call runtime callback. An attacker can invoke this callback with crafted context and object parameters to bypass sandbox restrictions, recover the host Function constructor, and execute arbitrary host JavaScript code. This vulnerability is addressed in SandboxJS version 0.9.6.
Potential Impact
Successful exploitation allows an attacker to execute arbitrary JavaScript code on the host environment, bypassing sandbox restrictions. This can lead to full compromise of the host application or environment running SandboxJS. The CVSS score of 10.0 reflects the highest impact on confidentiality, integrity, and availability.
Mitigation Recommendations
Upgrade to SandboxJS version 0.9.6 or later, where this vulnerability is fixed. Since the vendor advisory confirms the fix in 0.9.6, applying this official update is the recommended remediation. No other mitigation or temporary workaround is indicated.
CVE-2026-43898: CWE-94: Improper Control of Generation of Code ('Code Injection') in nyariv SandboxJS
Description
SandboxJS is a JavaScript sandboxing library. Prior to 0.9.6, sandbox-defined functions expose Function.caller, allowing sandboxed code to recover the internal LispType.Call runtime callback. That callback can then be invoked with attacker-controlled fake context and obj values to extract blocked host statics, recover the real host Function constructor, and execute arbitrary host JavaScript. This vulnerability is fixed in 0.9.6.
CVSS v3.1
Score 10.0critical
Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
SandboxJS versions before 0.9.6 suffer from a code injection vulnerability (CWE-94) due to improper control over the generation of code. Specifically, sandbox-defined functions expose Function.caller, which allows sandboxed code to access the internal LispType.Call runtime callback. An attacker can invoke this callback with crafted context and object parameters to bypass sandbox restrictions, recover the host Function constructor, and execute arbitrary host JavaScript code. This vulnerability is addressed in SandboxJS version 0.9.6.
Potential Impact
Successful exploitation allows an attacker to execute arbitrary JavaScript code on the host environment, bypassing sandbox restrictions. This can lead to full compromise of the host application or environment running SandboxJS. The CVSS score of 10.0 reflects the highest impact on confidentiality, integrity, and availability.
Mitigation Recommendations
Upgrade to SandboxJS version 0.9.6 or later, where this vulnerability is fixed. Since the vendor advisory confirms the fix in 0.9.6, applying this official update is the recommended remediation. No other mitigation or temporary workaround is indicated.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- GitHub_M
- Date Reserved
- 2026-05-04T16:11:33.085Z
- Cvss Version
- 3.1
- State
- PUBLISHED
- Remediation Level
- null
Threat ID: 6a188377e29bf47b50179022
Added to database: 5/28/2026, 6:03:35 PM
Last enriched: 5/28/2026, 6:19:01 PM
Last updated: 5/29/2026, 4:52:53 PM
Views: 12
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