CVE-2026-31807

MEDIUM EPSS 35.6%
Published Mar 10, 20263mo ago · Modified Mar 11, 20263mo ago
6.4 CVSS 4.0
Medium
Find Similar
Published Mar 10, 2026 3mo ago
Last Modified Mar 11, 2026 3mo ago

Description

SiYuan is a personal knowledge management system. Prior to 3.5.10, SiYuan's SVG sanitizer (SanitizeSVG) blocks dangerous elements (<script>, <iframe>, <foreignobject>) and removes on* event handlers and javascript: in href attributes. However, it does NOT block SVG animation elements (<animate>, <set>) which can dynamically set attributes to dangerous values at runtime, bypassing the static sanitization. This allows an attacker to inject executable JavaScript into the unauthenticated /api/icon/getDynamicIcon endpoint (type=8), creating a reflected XSS. This is a bypass of the fix for CVE-2026-29183 (fixed in v3.5.9). This vulnerability is fixed in v3.5.10.

CVSS Details

Base Score
6.4
Exploitability
—
Impact
—
Vector string
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:N/SC:H/SI:H/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Attack Vector Network
Attack Complexity Low
Privileges Required None
User Interaction P
Scope X

Threat Intelligence

EPSS Exploit Probability
35.6% percentile
Exploit & Patch Status
Public Exploit Known
No Patch Available

Weaknesses 1

CWE-79 Cross-site Scripting Injection

Affected Products 1

VendorProductVersionRange
b3logsiyuan* <3.5.10

References 1

  • github.com https://github.com/siyuan-note/siyuan/security/advisories/GHSA-5hc8-qmg8-pw27
    ExploitVendor Advisory

Remediation

No remediation data recorded yet

Check vendor advisories and the NVD entry for patch availability.