{"id":"CVE-2026-77394","url":"https://www.cyber-defence.io/tools/cve/CVE-2026-77394","generatedAt":"2026-10-28T03:29:43.823Z","title":"The stored script runs in the COSMOS origin and can read localStorage.openc3Token, allowing theft of the victim's bearer token, account takeover, and actions with the victim's privileges.","description":"OpenC3 COSMOS provides the functionality needed to send commands to and receive data from one or more embedded systems. From 5.0.6 until 7.3.0, an authenticated actor with system_set permission can store a shared screen through POST /openc3-api/screen whose BUTTON widget action is evaluated by openc3-cosmos-init/plugins/packages/openc3-vue-common/src/widgets/ButtonWidget.vue in another operator's browser session when the button is activated. The stored script runs in the COSMOS origin and can read localStorage.openc3Token, allowing theft of the victim's bearer token, account takeover, and actions with the victim's privileges. The permissive content security policy contributes to execution but is not the primary root cause. This issue is fixed in version 7.3.0.","published":"2026-09-23T19:19:15.000Z","lastModified":"2026-09-23T20:17:16.000Z","status":"Deferred","sourceIdentifier":"security-advisories@github.com","cvss":{"version":"3.1","score":7.6,"severity":"HIGH","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:L/A:N"},"cwe":["CWE-79"],"affected":[],"epss":{"score":0.00417,"percentile":0.35811,"date":"2026-10-26","history":[{"date":"2026-09-24","score":0.0039,"percentile":0.30232}]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"high","text":"High impact if exploited, but EPSS currently rates exploitation as unlikely (0.42%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit."},"changes":[{"kind":"new","label":"New CVE","at":"2026-09-23T19:19:15.000Z","detail":{"score":"7.6","severity":"HIGH","publishedAt":"2026-09-23T19:19:15.343Z"},"summary":"New CVE, high severity (CVSS 7.6)."}],"references":[{"url":"https://github.com/OpenC3/cosmos/commit/10371f8f410b9ad588f98dfa3befaaacb6587cd3","source":"security-advisories@github.com"},{"url":"https://github.com/OpenC3/cosmos/pull/3560","source":"security-advisories@github.com"},{"url":"https://github.com/OpenC3/cosmos/releases/tag/v7.3.0","source":"security-advisories@github.com"},{"url":"https://github.com/OpenC3/cosmos/security/advisories/GHSA-gvf2-2rh5-mpgf","source":"security-advisories@github.com"},{"url":"https://github.com/OpenC3/cosmos/security/advisories/GHSA-gvf2-2rh5-mpgf","source":"134c704f-9b21-4f2e-91b3-4a467353bcc0"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-77394","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}