{"id":"CVE-2026-49143","summary":"BrowserStack Runner 0.9.5 Unauthenticated RCE via /_log HTTP Handler","details":"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.","aliases":["GHSA-6vr3-7wcx-v5g5"],"modified":"2026-06-18T03:57:18.141349255Z","published":"2026-06-02T20:31:16.903Z","database_specific":{"cna_assigner":"VulnCheck","cwe_ids":["CWE-94"],"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/49xxx/CVE-2026-49143.json"},"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/49xxx/CVE-2026-49143.json"},{"type":"ADVISORY","url":"https://github.com/browserstack/browserstack-runner/security/advisories/GHSA-6vr3-7wcx-v5g5"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-49143"},{"type":"ADVISORY","url":"https://www.vulncheck.com/advisories/browserstack-runner-unauthenticated-rce-via-log-http-handler"},{"type":"PACKAGE","url":"https://github.com/browserstack/browserstack-runner"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/browserstack/browserstack-runner","events":[{"introduced":"0"},{"fixed":"1e85e559951bdf97ffe2a7c744ee67ca83589fde"}],"database_specific":{"source":["AFFECTED_FIELD","DESCRIPTION"],"extracted_events":[{"introduced":"0"},{"last_affected":"0.9.5"},{"introduced":"0"},{"fixed":"0.9.5"}]}}],"versions":["0.9.1","v0.7.0","v0.6.0","v0.5.1","v0.4.4","v0.4.3","v0.4.2","v0.4.1","v0.4.0","v0.3.8","v0.3.7","v0.3.6","v0.3.5","v0.3.4","v0.3.3","v0.3.2","v0.3.1","0.3.0","0.2.3","0.2.2","0.2.0","0.1.14","v0.1.11","v0.1.10","v0.1.9","v0.1.8"],"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2026-49143.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V4","score":"CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N"}]}