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Response snapshot Nov 9, 2026, 02:36 UTC

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VulnerabilityCVE-2026-41894

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

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().

At a glance

Exploited
Not known
Severity
7.1 High (CVSS 4.0)
Chance of exploitation
0.4% in the next 30 days
Sources
1 source

What to do

GitHub lists first patched versions: github.com/siyuan-note/siyuan/kernel: 3.6.5. Confirm the affected range and upgrade guidance in the exact advisory.

Read GitHub-reviewed advisory GHSA-hjh7-r5w8-5872 (opens a new tab)

What happened

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:

Continue reading
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:

1. Attacker sends: GET /export/%252e%252e/siyuan.db 2. Go HTTP decodes %25 → %, result: URL.Path = /export/%2e%2e/siyuan.db 3. Go's path cleaner sees %2e%2e as literal characters (not ..), no redirect occurs 4. url.PathUnescape("%2e%2e") decodes to .. 5. filepath.Join(exportBaseDir, "../siyuan.db") resolves to /temp/siyuan.db

The CVE-2026-30869 fix added IsSensitivePath() which blocks /conf/ and OS-level paths (/etc, /root, etc.). However, it does NOT block: - /temp/siyuan.db — full document database - /temp/blocktree.db — block tree database - /temp/siyuan.log — kernel log - /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](https://github.com/user-attachments/files/26866234/poc.zip) Please extract the uploaded compressed file before proceeding

1. docker compose up -d --build 2. 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 package ranges reported by GitHub: github.com/siyuan-note/siyuan/kernel: < 3.6.5

Scores and how they were measured

CVSS base severity

7.1

Version 4.0As of

CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N

Measurement source (opens a new tab)

How bad it is if exploited. Not a prediction of exploitation or proof you are exposed.

EPSS probability

0.4%

Scored Percentile 31.6%

Model and measurement source (opens a new tab)

A model's estimate of exploitation in the next 30 days, not certainty or your own risk.

Related technology

Sources

  1. Primary source

    GitHub-reviewed advisory GHSA-hjh7-r5w8-5872 (opens a new tab)

    The public advisory supplies the description, affected package/version ranges, and any listed CVSS metric. GitHub review is not local review.

    Published Checked

  2. Primary source

    GitHub public advisory API page (opens a new tab)

    The API page supplied GHSA-hjh7-r5w8-5872, its actual identifiers, source dates, and structured metrics.

    Published Date not suppliedChecked

  3. Primary source

    FIRST measured EPSS score (opens a new tab)

    Measured EPSS probability and percentile for CVE-2026-41894, scored 2026-11-08. This is a model estimate, not proof of exposure.

    Published Checked

Cite this record

For factual claims, cite the primary sources above; cite KEVWire for its compilation, dates, and classifications.

APA

KEVWire. (2026, November 9). SiYuan: Path Traversal via Double URL Encoding in `/export/` Endpoint (Incomplete Fix Bypass for CVE-2026-30869) (CVE-2026-41894). https://kevwire.com/record/CVE-2026-41894

MLA

"SiYuan: Path Traversal via Double URL Encoding in `/export/` Endpoint (Incomplete Fix Bypass for CVE-2026-30869) (CVE-2026-41894)." KEVWire, 9 Nov. 2026, kevwire.com/record/CVE-2026-41894.

Chicago

KEVWire. "SiYuan: Path Traversal via Double URL Encoding in `/export/` Endpoint (Incomplete Fix Bypass for CVE-2026-30869) (CVE-2026-41894)." Last modified November 9, 2026. https://kevwire.com/record/CVE-2026-41894.

Evidence summary (plain text)

SiYuan: Path Traversal via Double URL Encoding in `/export/` Endpoint (Incomplete Fix Bypass for CVE-2026-30869) (Apr 22, 2026).
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.

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

Go's HTTP server already decodes percent-encoded characters once during request parsing.
CVSS 7.1 (version 4.0; evidence as of Nov 9, 2026; https://github.com/advisories/GHSA-hjh7-r5w8-5872).
EPSS 0.4% for the following 30 days, scored Nov 8, 2026 (https://api.first.org/data/v1/epss?cve=CVE-2026-41894&date=2026-11-08).
Sources:
GitHub-reviewed advisory GHSA-hjh7-r5w8-5872: https://github.com/advisories/GHSA-hjh7-r5w8-5872
GitHub public advisory API page: https://api.github.com/advisories?type=reviewed&per_page=100&sort=updated&direction=desc
FIRST measured EPSS score: https://api.first.org/data/v1/epss?cve=CVE-2026-41894&date=2026-11-08
Record ID: CVE-2026-41894.
Record origin: Ingested record.
AI evidence: Not assessed.
Known exploitation: Not assessed.
Zero-day status: Not assessed. KEV membership alone does not establish zero-day status.
About this data

This record was ingested from a data source. Retrieved: Nov 9, 2026, 02:35 UTC. Ingestion is not an independent editorial investigation.

A CISA KEV listing documents known exploitation, not necessarily a zero-day; absence from the catalog does not prove a vulnerability has never been exploited.

Technology tags indicate possible relevance, not verified exposure. Confirm the affected product, version, and configuration against your own inventory; KEVWire does not scan your systems.

A personal reading checklist on this device, not verified remediation.

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