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Mallory
MediumPublic exploit

Arbitrary File Read via html2BlockDOM file:// handling in SiYuan Desktop

IdentifiersCVE-2026-32938CWE-22· Improper Limitation of a Pathname…

CVE-2026-32938 affects SiYuan, a personal knowledge management system. In SiYuan desktop versions 3.6.0 and earlier, the /api/lute/html2BlockDOM endpoint processes pasted HTML containing file:// links and copies the referenced local files into the workspace assets directory. The vulnerable behavior does not validate the referenced paths against a sensitive-path allow/deny list before copying. Because the copied content becomes accessible through GET /assets/*path, which requires only authentication, an authenticated publish-service visitor can induce the desktop kernel to copy arbitrary readable local sensitive files and then retrieve them. The issue results in unauthorized exposure of local files from the host running the SiYuan desktop application. The vulnerability is fixed in version 3.6.1.

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ANALYST BRIEF

Impact, mitigation & remediation

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Impact

What an attacker gets, and what they’ve been doing with it.

Successful exploitation allows an authenticated low-privilege attacker, specifically a publish-service visitor, to exfiltrate arbitrary readable sensitive files from the local system hosting the SiYuan desktop instance. This can expose credentials, configuration files, tokens, private keys, documents, and other sensitive local data. The advisory also indicates potential integrity and availability impact, but the primary demonstrated impact is high-severity confidentiality loss through arbitrary file disclosure.

Mitigation

If you can’t patch tonight, do this now.

If immediate upgrade is not possible, restrict or disable access for publish-service visitors and other low-privilege authenticated users, especially where the desktop application is exposed to untrusted content. Avoid pasting or processing untrusted HTML containing file:// references. Limit access to the /assets/*path endpoint where feasible, and run the SiYuan desktop application with the minimum filesystem privileges necessary so that sensitive local files are not readable by the application process. Network and application-layer controls that prevent untrusted authenticated users from invoking /api/lute/html2BlockDOM can further reduce exposure.

Remediation

Patch, then assume compromise.

Upgrade SiYuan to version 3.6.1 or later, which fixes the unsafe file-copy behavior in /api/lute/html2BlockDOM. The advisory references fixing commit 294b8b429dea152cd1df522cddf406054c1619ad and the SiYuan v3.6.1 release as remediation sources.
PUBLIC EXPLOITS

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VALID 0 / 0 TOTALView more in app

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EXPOSURE SURFACE

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VendorProductType
B3logSiyuanapplication

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Social activity6

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