CVE-2026-54066
HighExploitedPublic exploitPrior to 3.7.0, the patch for CVE-2026-41894 ("Path Traversal via Double URL Encoding") sanitized the /export/ route but the identical root cause remains in the /assets/*path route.
Published Jun 24, 2026 · Updated Aug 12, 2026 · Also known as EUVD-2026-39122, GHSA-p4m3-mgmm-c664, GO-2026-5964
Key Facts
Patch immediately- CVE-2026-54066 is a high-severity vulnerability (CVSS 7.5 v3.1) affecting github.com/siyuan-note/siyuan/kernel (go), SiYuan.
- It is exploited in the wild, listed in Industry KEV feed, CIRCL KEV since Aug 3, 2026. Public exploit code is available.
- EPSS estimates a 2.4% probability of exploitation in the next 30 days.
- Fixed versions are available, including github.com/siyuan-note/siyuan/kernel 0.0.0-20260628153353-2d5d72223df4, SiYuan 3.7.0.
- Brandefense priority: patch immediately, because it is listed as exploited in the wild.
CVSS v3.1
7.5
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
EPSS (30-day exploit likelihood)
2.4%
Higher than 83.6% of all scored CVEs
Exploited in the wild
Yes
2 catalog listings
Public exploit code
Available
Proof-of-concept or weaponized module
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Description
SiYuan is an open-source personal knowledge management system. Prior to 3.7.0, the patch for CVE-2026-41894 ("Path Traversal via Double URL Encoding") sanitized the /export/ route but the identical root cause remains in the /assets/*path route. In publish mode (anonymous read-only HTTP endpoint, default port 6808), an unauthenticated remote attacker can read arbitrary files inside WorkspaceDir — including conf/conf.json (which contains the AccessAuthCode SHA256 hash, API token, and sync keys), temp/siyuan.db, temp/blocktree.db, and siyuan.log — by double-URL-encoding .. segments. This vulnerability is fixed in 3.7.0.
Known-Exploited Catalog Listings
| Catalog | Added | Remediation due | Ransomware use |
|---|---|---|---|
| Industry KEV feed | Aug 3, 2026 | n/a | Not reported |
| CIRCL KEV | Aug 3, 2026 | n/a | Not reported |
Required action: Apply remediations or mitigations per vendor instructions or discontinue use of the product if remediation or mitigations are unavailable.
Affected Products
2 affected entries in total| Product | Affected versions | Fixed in |
|---|---|---|
| github.com/siyuan-note/siyuan/kernelgo | See advisory | 0.0.0-20260628153353-2d5d72223df4 |
| SiYuan | See advisory | 3.7.0 |
Patched Releases
github.com/siyuan-note/siyuan/kernel
0.0.0-20260628153353-2d5d72223df4
SiYuan
3.7.0
Timeline
Publicly disclosed
Jun 24, 2026
Added to Industry KEV feed
Aug 3, 2026
Added to CIRCL KEV
Aug 3, 2026
Last updated
Aug 12, 2026
Weakness Type
- CWE-22 Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
- CWE-23 Relative Path Traversal
- CWE-1188 Initialization of a Resource with an Insecure Default
References
- advisoryGHSA advisory
- advisoryhttps://github.com/CVEProject/cvelistV5/tree/main/cves/2026/54xxx/CVE-2026-54066.json
- advisoryhttps://nvd.nist.gov/vuln/detail/CVE-2026-54066
- exploitVulnCheck exploitation report
- exploitVulnCheck exploitation report
FAQ
Common Questions.
SiYuan is an open-source personal knowledge management system.
Affected: github.com/siyuan-note/siyuan/kernel (go); SiYuan. The full list is in the CVE brief.
It is exploited in the wild, listed in Industry KEV feed, CIRCL KEV since Aug 3, 2026.
No, it is not currently listed in the CISA Known Exploited Vulnerabilities catalog.
Public exploit code is available.
Fixed versions are available, including github.com/siyuan-note/siyuan/kernel 0.0.0-20260628153353-2d5d72223df4, SiYuan 3.7.0.
Brandefense priority: patch immediately, because it is listed as exploited in the wild.
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