BrowserStack Runner through 0.9.5 contains a remote code execution vulnerability in the /_log HTTP handler that allows unauthenticated network-adjacent attackers to execute arbitrary code by submitting crafted JSON request bodies to the handler, which passes user-supplied data to vm.runInNewContext() combined with eval(). Attackers can escape the Node.js vm sandbox by leveraging a host-context Function reference through util.format to access the host process via this.constructor.constructor, achieving full remote code execution on the underlying system without any authentication.
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History
Wed, 03 Jun 2026 02:30:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | BrowserStack Runner through 0.9.5 contains a remote code execution vulnerability in the /_log HTTP handler that allows unauthenticated network-adjacent attackers to execute arbitrary code by submitting crafted JSON request bodies to the handler, which passes user-supplied data to vm.runInNewContext() combined with eval(). Attackers can escape the Node.js vm sandbox by leveraging a host-context Function reference through util.format to access the host process via this.constructor.constructor, achieving full remote code execution on the underlying system without any authentication. | |
| Title | BrowserStack Runner 0.9.5 Unauthenticated RCE via /_log HTTP Handler | |
| Weaknesses | CWE-94 | |
| References |
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cvssV3_1
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Status: PUBLISHED
Assigner: VulnCheck
Published:
Updated: 2026-06-02T20:31:16.903Z
Reserved: 2026-05-27T17:40:12.739Z
Link: CVE-2026-49143
No data.
Status : Received
Published: 2026-06-02T21:16:28.070
Modified: 2026-06-02T21:16:28.070
Link: CVE-2026-49143
No data.
OpenCVE Enrichment
Updated: 2026-06-03T04:30:05Z