CVE-2026-59855
XSS in SiYuan Electron app allows JS injection and OS command execution
Is CVE-2026-59855 being exploited?
Not confirmed. CVE-2026-59855 does not appear in CISA's Known Exploited Vulnerabilities catalog, which records only exploitation that has been observed and reported publicly. That is evidence of absence of a report, not evidence the flaw is unattacked. EPSS currently estimates a 0.53% probability of exploitation in the next 30 days.
How severe is CVE-2026-59855?
CVE-2026-59855 is rated High with a CVSS score of 8.6. Severity describes how bad exploitation would be, not how likely it is: pair it with exploitation evidence before deciding what to patch first.
Is there a patch for CVE-2026-59855?
Yes. A fix has been recorded for CVE-2026-59855. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-59855 affect?
CVE-2026-59855 affects SiYuan < 3.7.1, SiYuan Electron desktop client (renderer). Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-59855?
Update SiYuan to 3.7.1 immediately
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Crafted asset link breaks src, injects JavaScript in Electron renderer enabling execution of OS commands (remote code execution on affected client).
Patch when possible
- affected< 3.7.1
As published in the CVE Program record. A version outside these ranges is not a statement that it is unaffected — vendors sometimes understate a range, and distribution-backported builds carry upstream numbers that do not reflect what was patched into them.