SiYuan through 3.8.4 fails to escape heading style attributes when rendering outline and bookmark dock HTML, allowing stored cross-site scripting. Attackers can supply crafted notebooks or call administrative endpoints to inject malicious style values that execute in the Electron renderer with full system access.
CVE-2026-93923
HIGHPre-NVD 8.88.8
EchelonGraph scoreLOW confidence
This high-severity CVE scores 8.8 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit-prediction score not yet available (the EPSS model rescores nightly; freshly-published CVEs typically appear within 48 hours). GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).
Triggered by: NVD CVSS baseline
Sources: secondary
8.8EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
- High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: —CVSS: 8.8Exploit: None knownExposed: 0
No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.
- CVSS v3
- 8.8
- EG Score
- 8.8(low)
- EG Risk
- 44(Track)EG Risk 44/100SSVC: Track
EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).
How it’s computedSeverity88% × 45%Exploitation0% × 40%Automatability30% × 15%Action: Routine — remediate on your standard cadence. - EPSS PROB
- —
- EPSS %ILE
- —
- KEV
- Not listed
Published
September 18, 2026
Last Modified
September 19, 2026
Advisory Details (6)
Auto-updated Sep 18, 2026🔬 Proof of concept available. Patch available. Sources: github.
generic
SiYuan through 3.8.4 Stored XSS via Heading Style Attribute | Advisories | VulnCheck
https://www.vulncheck.com/advisories/siyuan-through-3.8.4-stored-xss-via-heading-style-attributegeneric
siyuan/app/src/util/Tree.ts at v3.8.4 · siyuan-note/siyuan · GitHub
https://github.com/siyuan-note/siyuan/blob/v3.8.4/app/src/util/Tree.ts#L194generic
siyuan/app/src/util/Tree.ts at v3.8.4 · siyuan-note/siyuan · GitHub
https://github.com/siyuan-note/siyuan/blob/v3.8.4/app/src/util/Tree.ts#L133generic
siyuan/kernel/model/render.go at v3.8.4 · siyuan-note/siyuan · GitHub
https://github.com/siyuan-note/siyuan/blob/v3.8.4/kernel/model/render.go#L71-L76generic
GitHub - siyuan-note/siyuan: An open-source, privacy-first, self-hosted knowledge workspace where humans and AI agents work together 开源、隐私优先、自托管的知识工作空间，让人与智能体在此协作 · GitHub
https://github.com/siyuan-note/siyuangithub Patch Available🟡 PoC Available
Stored XSS via Unescaped Heading `style` IAL in the Outline Dock Tree Renderer Leading to Remote Code Execution in Electron · Advisory · siyuan-note/siyuan · GitHub
https://github.com/siyuan-note/siyuan/security/advisories/GHSA-928g-4hfq-qwvxVendor Advisories for CVE-2026-93923(1)
These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.
Weakness Classification(1)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Data Freshness Timeline
(refreshed 3× in last 7d / 3× in last 30d)
Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.
- 2026-09-19 00:21 UTCEG score recompute
- 2026-09-18 23:23 UTCEG score recompute
- 2026-09-18 23:22 UTCMITRE cvelistV5first tracked
Related CVEs(same CWE)
Frequently asked(4)
What is CVE-2026-93923?
CVE-2026-93923 is a high vulnerability published on September 18, 2026. SiYuan through 3.8.4 fails to escape heading style attributes when rendering outline and bookmark dock HTML, allowing stored cross-site scripting. Attackers can supply crafted notebooks or call administrative endpoints to inject malicious style values that execute in the Electron renderer with full…
When was CVE-2026-93923 disclosed?
CVE-2026-93923 was first published in the National Vulnerability Database on September 18, 2026, with the most recent update on September 19, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
What is the CVSS score of CVE-2026-93923?
CVE-2026-93923 has a CVSS v3 base score of 8.8 (NVD). The EG score is currently aggregating — additional source signals are being incorporated as they become available..
How do I remediate CVE-2026-93923?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-93923, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.
Dependency Blast Radius
Explore the affected products and dependency analysis for CVE-2026-93923
Is Your Infrastructure Affected by CVE-2026-93923?
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