How should we interpret CVSS severity scores?

CVSS estimates technical severity, but it does not automatically equal business risk. Prioritize using context like internet exposure, asset criticality, known exploitation, and whether compensating controls exist. A Medium CVSS on an exposed production system can be more urgent than a Critical on an isolated non-production host.

Vulnerability Database

Q: What is a Vulnerability (CVE) and why does it matter?

A security vulnerability is a weakness in software, hardware, or configuration that can be exploited to compromise confidentiality, integrity, or availability. Many vulnerabilities are tracked as CVEs (Common Vulnerabilities and Exposures), which provide a standardized identifier so teams can coordinate patching, mitigation, and risk assessment across tools and vendors.

Q: What's the difference between a vulnerability, an exploit, and a zero-day?

A vulnerability is the underlying weakness. An exploit is the method or code used to take advantage of it. A zero-day is a vulnerability that is unknown to the vendor or has no publicly available fix when attackers begin using it. Risk increases sharply when exploitation becomes reliable or widespread.

Q: Why do vulnerabilities keep reappearing in our environment?

Recurring findings usually come from incomplete asset discovery, inconsistent patch management, inherited images, and configuration drift. In modern environments, you also need to watch the software supply chain: dependencies, containers, build pipelines, and third-party services can reintroduce the same weakness even after you patch a single host.

Q: How do we prioritize remediation without burning out the team?

Use a repeatable triage model: focus first on externally exposed assets, high-value systems (identity, VPN, email, production), vulnerabilities with known exploits, and issues that enable remote code execution or privilege escalation. Then enforce patch SLAs and track progress so remediation is steady, not reactive.

Q: How can SynScan help reduce vulnerability risk over time?

SynScan combines attack surface monitoring and continuous security auditing to keep your inventory current, flag high-impact vulnerabilities early, and help you turn raw findings into a practical remediation plan.

357,831

Total vulnerabilities in the database

SiYuan: Path Traversal via Double URL Encoding in `/export/` Endpoint (Incomplete Fix Bypass for CVE-2026-30869) — github.com/siyuan-note/siyuan/kernel

Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')

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, &quot;/export/&quot;)
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.

Published: Apr 22, 2026
Updated: Apr 23, 2026
GHSA: GHSA-hjh7-r5w8-5872
Severity: High
Exploit:
CISA KEV:

No technical information available.

CWEs:

CWE-22

OWASP TOP 10:

A5 - Broken Access Control

Affected Software
References

Software	From	Fixed in
github.com/siyuan-note/siyuan/kernel	-	3.6.5

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Frequently Asked Questions

What is a Vulnerability (CVE) and why does it matter?

A security vulnerability is a weakness in software, hardware, or configuration that can be exploited to compromise confidentiality, integrity, or availability. Many vulnerabilities are tracked as CVEs (Common Vulnerabilities and Exposures), which provide a standardized identifier so teams can coordinate patching, mitigation, and risk assessment across tools and vendors.

CVSS (Common Vulnerability Scoring System) estimates technical severity, but it doesn't automatically equal business risk. Prioritize using context like internet exposure, affected asset criticality, known exploitation (proof-of-concept or in-the-wild), and whether compensating controls exist. A "Medium" CVSS on an exposed, production system can be more urgent than a "Critical" on an isolated, non-production host.

A vulnerability is the underlying weakness. An exploit is the method or code used to take advantage of it. A zero-day is a vulnerability that is unknown to the vendor or has no publicly available fix when attackers begin using it. In practice, risk increases sharply when exploitation becomes reliable or widespread.

Recurring findings usually come from incomplete Asset Discovery, inconsistent patch management, inherited images, and configuration drift. In modern environments, you also need to watch the software supply chain: dependencies, containers, build pipelines, and third-party services can reintroduce the same weakness even after you patch a single host. Unknown or unmanaged assets (often called Shadow IT) are a common reason the same issues resurface.

Use a simple, repeatable triage model: focus first on externally exposed assets, high-value systems (identity, VPN, email, production), vulnerabilities with known exploits, and issues that enable remote code execution or privilege escalation. Then enforce patch SLAs and track progress using consistent metrics so remediation is steady, not reactive.

SynScan combines attack surface monitoring and continuous security auditing to keep your inventory current, flag high-impact vulnerabilities early, and help you turn raw findings into a practical remediation plan.