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CVE-2026-33067

B3log Siyuan remote code execution

9.0 CRITICALPublic exploitEPSS 0.65%
  1. Published20 Mar 2026

Description

SiYuan is a personal knowledge management system. Versions 3.6.0 and below render package metadata fields (displayName, description) using template literals without HTML escaping. A malicious package author can inject arbitrary HTML/JavaScript into these fields, which executes automatically when any user browses the Bazaar page. Because SiYuan's Electron configuration enables nodeIntegration: true with contextIsolation: false, this XSS escalates directly to full Remote Code Execution on the victim's operating system — with zero user interaction beyond opening the marketplace tab. This issue has been fixed in version 3.6.1.

CVSS 3.1 breakdown

Attack vectorNetwork
Attack complexityLow
Privileges requiredLow
User interactionRequired
ScopeChanged
ConfidentialityHigh
IntegrityHigh
AvailabilityHigh
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:H

Affected products

B3log Siyuan< 3.6.1

Remediation

Fixed in
B3log Siyuan≥ 3.6.1

Frequently asked

Is CVE-2026-33067 being actively exploited?

CVE-2026-33067 is not in the CISA KEV catalog. A public exploit reference exists, so treat it as exploitable. Its EPSS exploit probability is 0.65%.

How severe is CVE-2026-33067?

CVE-2026-33067 has a CVSS 3.1 base score of 9.0, rated critical. EPSS estimates a 0.65% probability of exploitation.

Which products are affected by CVE-2026-33067?

Affected products include B3log Siyuan.

How do I fix CVE-2026-33067?

Upgrade affected software to a fixed version, for example B3log Siyuan 3.6.1 or later, then confirm no affected versions remain in your inventory.

How Secuno handles this

Secuno correlates vulnerabilities like CVE-2026-33067 against the real software inventory on every managed device, as each hourly inventory arrives. Rather than a static severity, each match is scored in context: exploit availability, EPSS, the asset's exposure, and business criticality decide where it lands in the queue. If an affected version is present anywhere across your portfolio, it surfaces automatically with a prioritised remediation path.

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Data from the NVD, CISA KEV catalog and FIRST EPSS. CVSS 3.1 base score shown where available.