SiYuan has a File Read Interface Case Bypass Vulnerability

published 2026-01-28 9 mo ago modified 2026-06-17 4 mo ago also EUVD-2026-6758 , GHSA-f72r-2h5j-7639 , GO-2026-4386

cvss: 7.5; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.6%; EPSS 0.6% chance of exploitation in 30 days, percentile 49%
public exploits: 0; none known

SiYuan is a personal knowledge management system. Prior to 3.5.5, the /api/file/getFile endpoint uses case-sensitive string equality checks to block access to sensitive files. On case-insensitive file systems such as Windows, attackers can bypass restrictions using mixed-case paths and read protected configuration files. This vulnerability is fixed in 3.5.5.

Patch / fix

fixed in 1 links 2

b3log siyuan 3.5.5

github.com/siyuan-note/siyuan@1f02650 commit
github.com/siyuan-note/siyuan/releases/tag/v3.5.5 release

CISA SSVC

Exploitation: Proof of concept is public
Automatable: yes
Technical impact: partial
Assessed: 8 mo ago (2026-02-10)

Exploit prediction

0.60% chance of exploitation in the next 30 days, higher than 49% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

github.com https://github.com/siyuan-note/siyuan/security/advisories/GHSA-f72r-2h5j-7639 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by	version	score	vector
CNA	3.1	7.5	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
GitHub	3.1	7.5	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

Affected packages

ecosystem	package	affected	fixed in
go	github.com/siyuan-note/siyuan/kernel	<=0.0.0-20260126094835-d5d10dd41b0c all versions	no fix listed

Affected products

siyuan-note siyuan

Classification

Weakness

CWE-22 Improper Limitation of a Pathname to a Restricted Directory
CWE-178 Improper Handling of Case Sensitivity
CWE-426 Untrusted Search Path

References

github.com /siyuan-note/siyuan/commit/1f02650b3892d2ea3896242dd2422c30bda55e11
web
github.com /siyuan-note/siyuan/security/advisories/GHSA-f72r-2h5j-7639
web, exploit, vendor-advisory, advisory
github.com /siyuan-note/siyuan/releases/tag/v3.5.5
web, product, release-notes
nvd.nist.gov /vuln/detail/CVE-2026-25992
advisory
github.com /siyuan-note/siyuan
package

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.

Summary