What is CVE-2026-56395?
SiYuan before v3.6.1 fails to sanitize package metadata and README content in the Bazaar marketplace, allowing malicious package authors to inject arbitrary HTML and JavaScript. Attackers can achieve remote code execution on any user browsing the Bazaar by embedding XSS payloads in package displayName, description, or README fields, exploiting Electron's nodeIntegration setting to execute OS commands.
The record classifies CVE-2026-56395 under weakness class CWE-79. Its CVSS v3 base vector states that the flaw is reachable remotely over the network, needs no prior authentication, needs a user to take an action first, and has high impact on confidentiality, integrity, availability. 1 affected-product entry is recorded, across 1 vendor, listed below. The identifier was first published 106 days ago.
Severity and exploitation probability
- CVSS v3.1 base score
- 9.6 — CRITICAL
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H - CVSS v4.0 base score
- 9.4
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H - CISA KEV
- Not listed in the CISA Known Exploited Vulnerabilities catalog
- Threadlinqs priority
- 4.8/10 — a Threadlinqs composite of the CVSS base score, the EPSS percentile and public exploit availability
- Published
- 2026-06-21, last modified 2026-06-22
Is CVE-2026-56395 being exploited?
It currently carries a trending score of 30 in the Threadlinqs vulnerability feed.
Affected products and versions
- SiYuan: SiYuan
How to fix CVE-2026-56395
No vendor patch reference has been recorded for CVE-2026-56395 in the tracked sources. Follow the references below for a fix, and treat the products listed above as exposed until the vendor states otherwise.
Threat activity tracking CVE-2026-56395
No threat campaign in the Threadlinqs corpus currently references CVE-2026-56395, in its CVE list or as an indicator. The linkage is recomputed from the live corpus on every daily ingest, so this section fills in as soon as a tracked campaign cites the identifier.
Sources
Enriched from CVE.org, GitHub Security Advisories. Last verified by Threadlinqs on .