SiYuan before v3.7.2 Stored XSS to RCE via title-img IAL (CVE-2026-66396) | HOL Guard CVE

Unknown severity · Source severity not reportedCVE-2026-66396

SiYuan before v3.7.2 Stored XSS to RCE via title-img IAL

Answer in brief

CVE-2026-66396 records a Unknown severity vulnerability in SiYuan before v3.7.2 Stored XSS to RCE via title-img IAL. The current sources do not mark it as known exploited. The current feed maps siyuan-note/siyuan (generic). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Jul 27, 2026Updated Sep 17, 2026Source checked Sep 17, 2026First seen by HOL Sep 17, 2026Material review Sep 17, 2026

Upstream Advisory

Key facts

Risk: Unknown severitySource severity not reported
Exploitation: Not marked as known exploited
Affected software: 1 mapped package or product
Fix availability: Available

Why this deserves its current priority

A CVSS score is not reported in the current record. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps siyuan-note/siyuan (generic). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
siyuan-note/siyuangeneric	>=0 <3.7.2	3.7.2

Recommended response

Check inventory. Check lockfiles and deployed manifests for siyuan-note/siyuan.
Review the reported fix. Update siyuan-note/siyuan to 3.7.2 if you use the affected versions. Test the change in a non-production environment first.

Evidence timeline and material changes

Published upstream
Jul 27, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Sep 17, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Sep 17, 2026

Sources and claim methodology

Upstream source description

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.

Quoted source text, attributed separately from HOL analysis.