CVE-2026-66396
SiYuan before v3.7.2 Stored XSS to RCE via title-img IAL
SiYuan before v3.7.2 fails to escape the title-img Individual Attribute List value when rendering Gallery and Kanban cover images, allowing stored cross-site scripting via unescaped style attribute interpolation. Attackers with editor permissions can inject onload handlers that execute arbitrary code in the Electron renderer with full Node.js access when victims open affected documents.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- High
- User interaction
- Passive
What an attacker can affect
- Confidentiality
- High
- Integrity
- High
- Availability
- High
Exploit likelihood
What each source reports
CVE List Score used
SiYuan before v3.7.2 Stored XSS to RCE via title-img IAL
SiYuan before v3.7.2 fails to escape the title-img Individual Attribute List value when rendering Gallery and Kanban cover images, allowing stored cross-site scripting via unescaped style attribute interpolation. Attackers with editor permissions can inject onload handlers that execute arbitrary code in the Electron renderer with full Node.js access when victims open affected documents.
- Record
CVE-2026-66396- CVSS 4.0
- 9.3 Critical
CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:P/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H - CVSS 3.1
- 8.4 High
CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:H/I:H/A:H - Weakness
- CWE-79
- Updated
- 2026-11-02
EUVDEUVD-2026-49329
SiYuan before v3.7.2 fails to escape the title-img Individual Attribute List value when rendering Gallery and Kanban cover images, allowing stored cross-site scripting via unescaped style attribute interpolation. Attackers with editor permissions can inject onload handlers that execute arbitrary code in the Electron renderer with full Node.js access when victims open affected documents.
- Record
EUVD-2026-49329- CVSS 4.0
- 9.3 Critical
CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:P/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-pwp5-qq97-mcqc
SiYuan before v3.7.2 fails to escape the title-img Individual Attribute List value when rendering...
SiYuan before v3.7.2 fails to escape the title-img Individual Attribute List value when rendering Gallery and Kanban cover images, allowing stored cross-site scripting via unescaped style attribute interpolation. Attackers with editor permissions can inject onload handlers that execute arbitrary code in the Electron renderer with full Node.js access when victims open affected documents.
- Record
GHSA-pwp5-qq97-mcqc- CVSS 4.0
- 9.3 Critical
CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:P/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/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 - CVSS 3.1
- 8.4 High
CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:H/I:H/A:H - Weakness
- CWE-79
- Updated
- 2026-11-02
NVD
SiYuan before v3.7.2 fails to escape the title-img Individual Attribute List value when rendering Gallery and Kanban cover images, allowing stored cross-site scripting via unescaped style attribute interpolation. Attackers with editor permissions can inject onload handlers that execute arbitrary code in the Electron renderer with full Node.js access when victims open affected documents.
- Record
CVE-2026-66396- CVSS 4.0
- 9.3 Critical
CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:P/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/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 - CVSS 3.1
- 8.4 High
CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:H/I:H/A:H - Weakness
- CWE-79
- Updated
- 2026-11-02
OSV
SiYuan before v3.7.2 Stored XSS to RCE via title-img IAL
SiYuan before v3.7.2 fails to escape the title-img Individual Attribute List value when rendering Gallery and Kanban cover images, allowing stored cross-site scripting via unescaped style attribute interpolation. Attackers with editor permissions can inject onload handlers that execute arbitrary code in the Electron renderer with full Node.js access when victims open affected documents.
- Record
CVE-2026-66396- CVSS 4.0
- 9.3 Critical
CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:P/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H - Weakness
- CWE-79
- Updated
- 2026-11-02
Affected products
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | CVE List, EUVD, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-66396 is a critical vulnerability (CVSS 9.3) in Siyuan-note Siyuan, published July 27, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.54%, the 45th percentile. No source names a fixed version.
References
github.com/siyuan-note/siyuan/security/advisories/GHSA-5rxg-wh59-mg34
vulncheck.com/advisories/siyuan-before-stored-xss-to-rce-via-title-img-ial
nvd.nist.gov/vuln/detail/CVE-2026-66396