Severity by source
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:N/SC:L/SI:L/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
Primary rating from GitHub Advisory · only source for this CVE.
CVSS VectorGitHub Advisory
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:N/SC:L/SI:L/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
Lifecycle Timeline
4DescriptionGitHub Advisory
SiYuan is an open-source personal knowledge management system. In versions 3.6.1 through 3.6.3, a prior fix for XSS in bazaar README rendering (incomplete fix for CVE-2026-33066) enabled the Lute HTML sanitizer, but the sanitizer does not block iframe tags, and its URL-prefix blocklist does not effectively filter srcdoc attributes which contain raw HTML rather than URLs. A malicious bazaar package author can include an iframe with a srcdoc attribute containing embedded scripts in their README. When other users view the package in SiYuan's marketplace UI, the payload executes in the Electron context with full application privileges, enabling arbitrary code execution on the user's machine. This issue has been fixed in version 3.6.4.
AnalysisAI
SiYuan 3.6.1 through 3.6.3 allows arbitrary code execution when users view malicious bazaar packages in the marketplace UI. The vulnerability stems from an incomplete XSS fix (for CVE-2026-33066) that enabled an HTML sanitizer but failed to block iframe tags with srcdoc attributes containing embedded scripts. …
Unlock full vulnerability intelligence
- Risk assessment & exploitation conditions
- Attack chain visualization
- Remediation with exact patch versions
- Threat intelligence from 22 sources
- Personal watchlist & email alerts
Free forever · No credit card required
Attack ChainAIDerived
Hypothetical attack flow derived from CVE metadata
Vulnerability AssessmentAI
| Exploitation | Exploitation requires: (1) SiYuan versions 3.6.1-3.6.3 running on the user's machine, (2) the bazaar marketplace feature enabled (default in standard installations), (3) the user actively browsing or viewing a malicious bazaar package in the marketplace UI, and (4) the attacker having the ability to publish or modify a bazaar package (either via compromised repository credentials or by creating a new malicious package repository linked to the bazaar). … Additional conditions and limiting factors are described in the full assessment. |
| Risk Assessment | CVSS 5.3 (PR:L/UI:N) indicates low to moderate severity, but the vulnerability carries significantly higher real-world risk. … Full risk analysis with EPSS, KEV, and SSVC signal comparison available after sign-in. |
| Exploit Scenario | An attacker creates or compromises a bazaar package repository and uploads a modified README.md containing an iframe with embedded JavaScript in a srcdoc attribute. When a SiYuan user browses the marketplace and views the package details, the README renders in the marketplace UI. … |
| Remediation | Upgrade immediately to SiYuan version 3.6.4 or later, which includes the corrected HTML sanitizer that now blocks iframe tags or properly sanitizes srcdoc attributes. … Detailed patch versions, workarounds, and compensating controls in full report. |
Threat intelligence, references, and detailed analysis are available after sign-in.
Share
External POC / Exploit Code
Leaving vuln.today