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CVE-2026-23852

B3log Siyuan remote code execution

9.6 CRITICALPublic exploitEPSS 0.79%
  1. Published19 Jan 2026

Description

SiYuan is a personal knowledge management system. Versions prior to 3.5.4 have a stored Cross-Site Scripting (XSS) vulnerability that allows an attacker to inject arbitrary HTML attributes into the `icon` attribute of a block via the `/api/attr/setBlockAttrs` API. The payload is later rendered in the dynamic icon feature in an unsanitized context, leading to stored XSS and, in the desktop environment, potential remote code execution (RCE). This issue bypasses the previous fix for issue `#15970` (XSS → RCE via dynamic icons). Version 3.5.4 contains an updated fix.

CVSS 3.1 breakdown

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

Affected products

B3log Siyuan< 3.5.4

Remediation

Fixed in
B3log Siyuan≥ 3.5.4

References

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Frequently asked

Is CVE-2026-23852 being actively exploited?

CVE-2026-23852 is not in the CISA KEV catalog. A public exploit reference exists, so treat it as exploitable. Its EPSS exploit probability is 0.79%.

How severe is CVE-2026-23852?

CVE-2026-23852 has a CVSS 3.1 base score of 9.6, rated critical. EPSS estimates a 0.79% probability of exploitation.

Which products are affected by CVE-2026-23852?

Affected products include B3log Siyuan.

How do I fix CVE-2026-23852?

Upgrade affected software to a fixed version, for example B3log Siyuan 3.5.4 or later, then confirm no affected versions remain in your inventory.

How Secuno handles this

Secuno correlates vulnerabilities like CVE-2026-23852 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.

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