CVE-2026-93923: SiYuan through 3.8.4 fails to escape heading style attributes when rendering outline and bookmark dock HTML, allowing…
CVE-2026-93923 analysis covering impact, affected products, versions, remediation, and cross-checked defender guidance.
CVE-2026-93923 is a vulnerability published by NVD on 9/19/2026.
What happened
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.
Affected products and versions
- NVD has not published a normalized affected-product configuration yet.
Severity and weakness
CVSS: HIGH 8.8. Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H.
Weaknesses: CWE-79.
Known exploitation
No CISA KEV entry is currently attached to the NVD record.
What defenders should do
- Identify whether the affected product and version range exists in production.
- Review vendor advisories and release notes before change windows.
- Patch, upgrade, disable the vulnerable component, or apply vendor mitigations.
- Verify the running version after deployment, not only the package inventory.
Official and supporting references
- No vendor advisory tagged by NVD at draft time.