CVE-2026-23645

SiYuan Vulnerable to Stored Cross-Site Scripting (XSS) via Unrestricted SVG File Upload

SiYuan is self-hosted, open source personal knowledge management software. Prior to 3.5.4-dev2, a Stored Cross-Site Scripting (XSS) vulnerability exists in SiYuan Note. The application does not sanitize uploaded SVG files. If a user uploads and views a malicious SVG file (e.g., imported from an untrusted source), arbitrary JavaScript code is executed in the context of their authenticated session. This vulnerability is fixed in 3.5.4-dev2.

CVSS 4.0 · 5.3 Medium EPSS < 1% KEV · Not listed

Vendors

B3log Siyuan

Products

Siyuan Siyuan

CVE-2026-25647

Lute has a Stored Cross-Site Scripting (XSS) via Markdown hyperlink

Lute is a structured Markdown engine supporting Go and JavaScript. Lute 1.7.6 and earlier (as used in SiYuan before) has a Stored Cross-Site Scripting (XSS) vulnerability in the Markdown rendering engine. An attacker can inject malicious JavaScript into a Markdown text/note. When another user clicks the rendered content, the script executes in the context of their session.

CVSS 3.1 · 4.6 Medium EPSS < 1% KEV · Not listed

Vendors

B3log Siyuan

Products

Siyuan Siyuan

CVE-2026-23847

SiYuan Vulnerable to Reflected Cross-Site Scripting (XSS) via /api/icon/getDynamicIcon

SiYuan is a personal knowledge management system. Versions prior to 3.5.4 are vulnerable to reflected cross-site scripting in /api/icon/getDynamicIcon due to unsanitized SVG input. The endpoint generates SVG images for text icons (type=8). The content query parameter is inserted directly into the SVG <text> tag without XML escaping. Since the response Content-Type is image/svg+xml, injecting unescaped tags allows breaking the XML structure and executing JavaScript. Version 3.5.4 patches the issue.]

CVSS 4.0 · 2.1 Low EPSS < 1% KEV · Not listed

Vendors

B3log Siyuan

Products

Siyuan Siyuan

CVE-2026-23850

SiYuan vulnerable to arbitrary file read

SiYuan is a personal knowledge management system. In versions prior to 3.5.4, the markdown feature allows unrestricted server side html-rendering which allows arbitrary file read (LFD). Version 3.5.4 fixes the issue.

CVSS 4.0 · 7.8 High EPSS < 1% KEV · Not listed

Vendors

B3log Siyuan

Products

Siyuan Siyuan

CVE-2026-23851

SiYuan Vulnerable to Arbitrary File Read via File Copy Functionality

SiYuan is a personal knowledge management system. Versions prior to 3.5.4 contain a logic vulnerability in the /api/file/globalCopyFiles endpoint. The function allows authenticated users to copy files from any location on the server's filesystem into the application's workspace without proper path validation. The vulnerability exists in the api/file.go source code. The function globalCopyFiles accepts a list of source paths (srcs) from the JSON request body. While the code checks if the source file exists using filelock.IsExist(src), it fails to validate whether the source path resides within the authorized workspace directory. Version 3.5.4 patches the issue.

CVSS 4.0 · 8.3 High EPSS < 1% KEV · Not listed

Vendors

B3log Siyuan

Products

Siyuan Siyuan

CVE-2026-23852

SiYuan vulnerable to Stored XSS / RCE via `setBlockAttrs` icon attribute

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 4.0 · 5.8 Medium EPSS < 1% KEV · Not listed

Vendors

B3log Siyuan

Products

Siyuan Siyuan

CVE-2026-25539

SiYuan has Arbitrary File Write via /api/file/copyFile leading to RCE

SiYuan is a personal knowledge management system. Prior to version 3.5.5, the /api/file/copyFile endpoint does not validate the dest parameter, allowing authenticated users to write files to arbitrary locations on the filesystem. This can lead to Remote Code Execution (RCE) by writing to sensitive locations such as cron jobs, SSH authorized_keys, or shell configuration files. This issue has been patched in version 3.5.5.

CVSS 3.1 · 9.1 Critical EPSS 1.1% KEV · Not listed

Vendors

B3log Siyuan

Products

Siyuan Siyuan

CVE-2026-25992

SiYuan has a File Read Interface Case Bypass Vulnerability

SiYuan is a personal knowledge management system. Prior to 3.5.5, the /api/file/getFile endpoint uses case-sensitive string equality checks to block access to sensitive files. On case-insensitive file systems such as Windows, attackers can bypass restrictions using mixed-case paths and read protected configuration files. This vulnerability is fixed in 3.5.5.

CVSS 3.1 · 7.5 High EPSS < 1% KEV · Not listed

Vendors

B3log Siyuan

Products

Siyuan Siyuan

CVE-2026-30869

SiYuan has a Path Traversal in /export Endpoint Allows Arbitrary File Read and Secret Leakage

SiYuan is a personal knowledge management system. Prior to 3.5.10, a path traversal vulnerability in the /export endpoint allows an attacker to read arbitrary files from the server filesystem. By exploiting double‑encoded traversal sequences, an attacker can access sensitive files such as conf/conf.json, which contains secrets including the API token, cookie signing key, and workspace access authentication code. Leaking these secrets may enable administrative access to the SiYuan kernel API, and in certain deployment scenarios could potentially be chained into remote code execution (RCE). This vulnerability is fixed in 3.5.10.

CVSS 3.1 · 9.3 Critical EPSS 1.2% KEV · Not listed

Vendors

B3log Siyuan

Products

Siyuan Siyuan

CVE-2026-31809

SiYuan has a SVG Sanitizer Bypass via Whitespace in `javascript:` URI — Unauthenticated XSS

SiYuan is a personal knowledge management system. Prior to 3.5.10, SiYuan's SVG sanitizer (SanitizeSVG) checks href attributes for the javascript: prefix using strings.HasPrefix(). However, inserting ASCII tab (&#9;), newline (&#10;), or carriage return (&#13;) characters inside the javascript: string bypasses this prefix check. Browsers strip these characters per the WHATWG URL specification before parsing the URL scheme, so the JavaScript still executes. This allows an attacker to inject executable JavaScript into the unauthenticated /api/icon/getDynamicIcon endpoint, creating a reflected XSS. This is a second bypass of the fix for CVE-2026-29183 (fixed in v3.5.9). This vulnerability is fixed in 3.5.10.

CVSS 4.0 · 6.4 Medium EPSS < 1% KEV · Not listed

Vendors

B3log Siyuan

Products

Siyuan Siyuan

CVE-2026-31807

SiYuan has a SVG Sanitizer Bypass via `<animate>` Element — Unauthenticated XSS

SiYuan is a personal knowledge management system. Prior to 3.5.10, SiYuan's SVG sanitizer (SanitizeSVG) blocks dangerous elements (<script>, <iframe>, <foreignobject>) and removes on* event handlers and javascript: in href attributes. However, it does NOT block SVG animation elements (<animate>, <set>) which can dynamically set attributes to dangerous values at runtime, bypassing the static sanitization. This allows an attacker to inject executable JavaScript into the unauthenticated /api/icon/getDynamicIcon endpoint (type=8), creating a reflected XSS. This is a bypass of the fix for CVE-2026-29183 (fixed in v3.5.9). This vulnerability is fixed in v3.5.10.

CVSS 4.0 · 6.4 Medium EPSS < 1% KEV · Not listed

Vendors

B3log Siyuan

Products

Siyuan Siyuan

CVE-2026-40107

SiYuan Affected by Zero-Click NTLM Hash Theft and Blind SSRF via Mermaid Diagram Rendering

SiYuan is a personal knowledge management system. Prior to 3.6.4, SiYuan configures Mermaid.js with securityLevel: "loose" and htmlLabels: true. In this mode, <img> tags with src attributes survive Mermaid's internal DOMPurify and land in SVG <foreignObject> blocks. The SVG is injected via innerHTML with no secondary sanitization. When a victim opens a note containing a malicious Mermaid diagram, the Electron client fetches the URL. On Windows, a protocol-relative URL (//attacker.com/image.png) resolves as a UNC path (\\attacker.com\image.png). Windows attempts SMB authentication automatically, sending the victim's NTLMv2 hash to the attacker. This vulnerability is fixed in 3.6.4.

CVSS 4.0 · 8.7 High EPSS < 1% KEV · Not listed

Vendors

B3log Siyuan

Products

Siyuan Siyuan

CVE-2026-29073

SiYuan: Direct SQL Query API accessible to Reader-level users enables unauthorized database access

SiYuan is a personal knowledge management system. Prior to version 3.6.0, the /api/query/sql lets a user run sql directly, but it only checks basic auth, not admin rights, any logged-in user, even readers, can run any sql query on the database. This issue has been patched in version 3.6.0.

CVSS 4.0 · 5.7 Medium EPSS < 1% KEV · Not listed

Vendors

B3log Siyuan

Products

Siyuan Siyuan

CVE-2026-29183

SiYuan: Unauthenticated reflected SVG XSS in `/api/icon/getDynamicIcon` (`type=8`) enables arbitrary JavaScript execution

SiYuan is a personal knowledge management system. Prior to version 3.5.9, an unauthenticated reflected XSS vulnerability exists in the dynamic icon API endpoint "GET /api/icon/getDynamicIcon" when type=8, attacker-controlled content is embedded into SVG output without escaping. Because the endpoint is unauthenticated and returns image/svg+xml, a crafted URL can inject executable SVG/HTML event handlers (for example onerror) and run JavaScript in the SiYuan web origin. This can be chained to perform authenticated API actions and exfiltrate sensitive data when a logged-in user opens the malicious link. This issue has been patched in version 3.5.9.

CVSS 3.1 · 9.3 Critical EPSS < 1% KEV · Not listed

Vendors

B3log Siyuan

Products

Siyuan Siyuan

CVE-2026-30926

SiYuan Note publish service authorization bypass allows low-privilege users to modify notebook content

SiYuan is a personal knowledge management system. Prior to 3.5.10, a privilege escalation vulnerability exists in the publish service of SiYuan Note that allows low-privilege publish accounts (RoleReader) to modify notebook content via the /api/block/appendHeadingChildren API endpoint. The endpoint requires only the model.CheckAuth role, which accepts RoleReader sessions, but it does not enforce stricter checks, such as CheckAdminRole or CheckReadonly. This allows remote authenticated publish users with read-only privileges to append new blocks to existing documents, compromising the integrity of stored notes.

CVSS 3.1 · 7.1 High EPSS < 1% KEV · Not listed

Vendors

B3log Siyuan

Products

Siyuan Siyuan

CVE-2026-39846

SiYuan affected by Remote Code Execution in the Electron desktop client via stored XSS in synced table captions

SiYuan is a personal knowledge management system. Prior to 3.6.4, a malicious note synced to another user can trigger remote code execution in the SiYuan Electron desktop client. The root cause is that table caption content is stored without safe escaping and later unescaped into rendered HTML, creating a stored XSS sink. Because the desktop renderer runs with nodeIntegration enabled and contextIsolation disabled, attacker-controlled JavaScript executes with access to Node.js APIs. In practice, an attacker can import a crafted note into a synced workspace, wait for the victim to sync, and achieve code execution when the victim opens the note. This vulnerability is fixed in 3.6.4.

CVSS 3.1 · 9.1 Critical EPSS < 1% KEV · Not listed

Vendors

B3log Siyuan

Products

Siyuan Siyuan

CVE-2026-34448

SiYuan: Stored XSS in Attribute View gallery/kanban cover rendering allows arbitrary command execution in the desktop client

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 · 9.1 Critical EPSS < 1% KEV · Not listed

Vendors

B3log Siyuan

Products

Siyuan Siyuan

CVE-2026-34585

SiYuan: Stored XSS in imported .sy.zip content leads to arbitrary command execution

SiYuan is a personal knowledge management system. Prior to version 3.6.2, a vulnerability allows crafted block attribute values to bypass server-side attribute escaping when an HTML entity is mixed with raw special characters. An attacker can embed a malicious IAL value inside a .sy document, package it as a .sy.zip, and have the victim import it through the normal Import -> SiYuan .sy.zip workflow. Once the note is opened, the malicious attribute breaks out of its original HTML context and injects an event handler, resulting in stored XSS. In the Electron desktop client, this XSS reaches remote code execution because injected JavaScript runs with access to Node/Electron APIs. This issue has been patched in version 3.6.2.

CVSS 3.1 · 8.6 High EPSS < 1% KEV · Not listed

Vendors

B3log Siyuan

Products

Siyuan Siyuan

CVE-2026-34605

SiYuan: Reflected XSS via SVG namespace prefix bypass in SanitizeSVG ( getDynamicIcon, unauthenticated )

SiYuan is a personal knowledge management system. From version 3.6.0 to before version 3.6.2, the SanitizeSVG function introduced in version 3.6.0 to fix XSS in the unauthenticated /api/icon/getDynamicIcon endpoint can be bypassed by using namespace-prefixed element names such as <x:script xmlns:x="http://www.w3.org/2000/svg">. The Go HTML5 parser records the element's tag as "x:script" rather than "script", so the tag check passes it through. The SVG is served with Content-Type: image/svg+xml and no Content Security Policy; when a browser opens the response directly, its XML parser resolves the prefix to the SVG namespace and executes the embedded script. This issue has been patched in version 3.6.2.

CVSS 4.0 · 8.6 High EPSS < 1% KEV · Not listed

Vendors

B3log Siyuan

Products

Siyuan Siyuan

CVE-2026-33669

SiYuan has Arbitrary Document Reading within the Publishing Service

SiYuan is a personal knowledge management system. Prior to version 3.6.2, document IDs were retrieved via the /api/file/readDir interface, and then the /api/block/getChildBlocks interface was used to view the content of all documents. Version 3.6.2 patches the issue.

CVSS 3.1 · 9.8 Critical EPSS < 1% KEV · Not listed

Vendors

B3log Siyuan

Products

Siyuan Siyuan