Skip to content

CVE-2026-34448

B3log Siyuan code injection

9.0 CRITICALPublic exploitEPSS 0.73%
  1. Published31 Mar 2026

Description

SiYuan is a personal knowledge management system. Prior to version 3.6.2, an attacker who can place a malicious URL in an Attribute View mAsse field can trigger stored XSS when a victim opens the Gallery or Kanban view with “Cover From -> Asset Field” enabled. The vulnerable code accepts arbitrary http(s) URLs without extensions as images, stores the attacker-controlled string in coverURL, and injects it directly into an <img src="..."> attribute without escaping. In the Electron desktop client, the injected JavaScript executes with nodeIntegration enabled and contextIsolation disabled, so the XSS reaches arbitrary OS command execution under the victim’s account. This issue has been patched in version 3.6.2.

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< 3.6.2

Remediation

Fixed in
B3log Siyuan≥ 3.6.2

Frequently asked

Is CVE-2026-34448 being actively exploited?

CVE-2026-34448 is not in the CISA KEV catalog. A public exploit reference exists, so treat it as exploitable. Its EPSS exploit probability is 0.73%.

How severe is CVE-2026-34448?

CVE-2026-34448 has a CVSS 3.1 base score of 9.0, rated critical. EPSS estimates a 0.73% probability of exploitation.

Which products are affected by CVE-2026-34448?

Affected products include B3log Siyuan.

How do I fix CVE-2026-34448?

Upgrade affected software to a fixed version, for example B3log Siyuan 3.6.2 or later, then confirm no affected versions remain in your inventory.

How Secuno handles this

Secuno correlates vulnerabilities like CVE-2026-34448 against the real software inventory on every managed device, every day. 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.

Get Patch this first every Monday

Five vulnerabilities that matter this week, ranked on real exploitation. Plain language, one email, no spam.

You can unsubscribe with one click from every issue. We handle your details as described in our privacy policy.

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