{"id":"CVE-2026-49143","aliases":["GHSA-6vr3-7wcx-v5g5"],"url":"https://o3.security/vulnerability/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.","published":"2026-06-02T20:31:16.903Z","modified":"2026-08-12T03:51:23.472063246Z","cvss":null,"epss":{"score":0.00392,"percentile":0.31948,"asOf":"2026-08-10"},"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"npm","name":"browserstack-runner","fixedVersion":null}],"fix":null,"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"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-08-12T03:51:23.472063246Z"}}