How severe is CVE-2026-41894?

No CVSS score has been assigned to CVE-2026-41894 yet. Review the advisory details and affected package list to assess your exposure.

Which packages are affected by CVE-2026-41894?

CVE-2026-41894 affects the following packages: github.com/siyuan-note/siyuan/kernel (Go). Ecosystems affected: Go.

How do I fix CVE-2026-41894?

Update github.com/siyuan-note/siyuan/kernel to 3.6.5 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-41894 is resolved across your whole dependency graph.

How do I detect CVE-2026-41894 in my Go dependencies?

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.

How do I mitigate CVE-2026-41894 if there is no patch (or I can't update yet)?

Resolve every user-supplied path to its canonical form and reject anything that escapes the intended directory, and run the component under an account that has no read or write access outside the directory it legitimately serves.

Is CVE-2026-41894 actively exploited in the wild?

No public exploit code has been indexed for CVE-2026-41894 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for CVE-2026-41894?

CVE-2026-41894 has an EPSS (Exploit Prediction Scoring System) score of 0.4%, placing it in the 32th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is CVE-2026-41894?

CVE-2026-41894 is classified as Path Traversal (CWE-22). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation. This is a high-impact weakness class that often enables remote code execution or data exposure.

When was CVE-2026-41894 published, and has it been updated?

CVE-2026-41894 was published on April 24, 2026 and was last updated on October 28, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

🐹 Go

Not in CISA KEV

CVE-2026-41894 — kernel

Fix: siyuan-note/siyuan@bb481e1

CVE-2026-41894 is a Path Traversal vulnerability in github.com/siyuan-note/siyuan/kernel. A fix is available for github.com/siyuan-note/siyuan/kernel — see the affected versions and patch details below.

SiYuan: Incomplete Fix Bypass for CVE-2026-30869: Path Traversal via Double URL Encoding in `/export/` Endpoint

Also known asGHSA-hjh7-r5w8-5872GO-2026-5429

Published

Apr 24, 2026

Updated

Oct 28, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

None indexed

Exploitation data as of Nov 5, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

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-2026-41894.

EPSS Exploitation Probability

via FIRST.org ↗

0.4%probability of exploitation in next 30 days

Lower Risk-0.09%

Lower risk than most CVEs32th percentile — riskier than 32% of all scored CVEsHighest risk

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

Real-World Exposure

1 pkg affected

🐹github.com/siyuan-note/siyuan/kernel

Real-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

The fix for CVE-2026-30869 in SiYuan v3.5.10 only added a denylist check (IsSensitivePath) but did not address the root cause — a redundant url.PathUnescape() call in serveExport(). An authenticated attacker can use double URL encoding (%252e%252e) to traverse directories and read arbitrary workspace files including the full SQLite database (siyuan.db), kernel log, and all user documents.

Details

In kernel/server/serve.go, the serveExport() function (line 314-320) processes file paths as follows:

filePath := strings.TrimPrefix(c.Request.URL.Path, "/export/")
decodedPath, err := url.PathUnescape(filePath)     // second decode
fullPath := filepath.Join(exportBaseDir, decodedPath)

Go's HTTP server already decodes percent-encoded characters once during request parsing. The additional url.PathUnescape() call creates a double-decode vulnerability:

Attacker sends: GET /export/%252e%252e/siyuan.db
Go HTTP decodes %25 → %, result: URL.Path = /export/%2e%2e/siyuan.db
Go's path cleaner sees %2e%2e as literal characters (not ..), no redirect occurs
url.PathUnescape("%2e%2e") decodes to ..
filepath.Join(exportBaseDir, "../siyuan.db") resolves to <workspace>/temp/siyuan.db

The CVE-2026-30869 fix added IsSensitivePath() which blocks <workspace>/conf/ and OS-level paths (/etc, /root, etc.). However, it does NOT block:

<workspace>/temp/siyuan.db — full document database
<workspace>/temp/blocktree.db — block tree database
<workspace>/temp/siyuan.log — kernel log
<workspace>/temp/asset_content.db — asset content database

Note: the /appearance/ handler in the same file correctly uses gulu.File.IsSubPath() to validate paths (line 447), but this check is missing from the /export/ handler.

PoC

poc.zip Please extract the uploaded compressed file before proceeding

docker compose up -d --build
sh poc.sh

Impact

Data exfiltration: An authenticated user (including low-privilege Publish/Reader users via the Publish service) can download the entire SQLite document database containing all blocks, documents, attributes, and full-text search indexes.
Information disclosure: Kernel log (siyuan.log) leaks internal server paths, versions, configuration details, and error messages.

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
🐹Go	`github.com/siyuan-note/siyuan/kernel`	all versions	3.6.5`go get github.com/siyuan-note/siyuan/kernel@v3.6.5`

Detection & mitigation playbook

Open-source dependency

Detect
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.
Fix
Update github.com/siyuan-note/siyuan/kernel to 3.6.5 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-41894 is resolved across your whole dependency graph.
Workarounds
Resolve every user-supplied path to its canonical form and reject anything that escapes the intended directory, and run the component under an account that has no read or write access outside the directory it legitimately serves.

Frequently Asked Questions

### Summary The fix for CVE-2026-30869 in SiYuan v3.5.10 only added a denylist check (`IsSensitivePath`) but did not address the root cause — a redundant `url.PathUnescape()` call in `serveExport()`. An authenticated attacker can use double URL encoding (`%252e%252e`) to traverse directories and read arbitrary workspace files including the full SQLite database (`siyuan.db`), kernel log, and all user documents. ### Details In `kernel/server/serve.go`, the `serveExport()` function (line 314-320) processes file paths as follows: ```go filePath := strings.TrimPrefix(c.Request.URL.Path, "/export/

O3 Security · Impact-Aware SCA

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