CVE-2026-54067
SiYuan: Stored XSS to RCE via CSS-snippet <style> breakout in renderSnippet()
Description
SiYuan is an open-source personal knowledge management system. Prior to 3.7.0, CSS snippet body containing </style> breaks out of its surrounding <style> tag when renderSnippet() interpolates it via insertAdjacentHTML. A payload like runs arbitrary JavaScript in the renderer. On Electron desktop builds the renderer runs with nodeIntegration:true, so require('child_process') is reachable from the injected handler and the XSS chains to host RCE. Snippets sync via the workspace repository, so an attacker with write access to any synced workspace plants the payload once and it fires on every device that pulls. The bug also bypasses the user's enabledCSS / enabledJS separation. A user who turned enabledJS off was making a deliberate call not to run untrusted JavaScript; the CSS path runs it anyway. This vulnerability is fixed in 3.7.0.
INFO
Published Date :
June 24, 2026, 10:16 p.m.
Last Modified :
Oct. 25, 2026, 11:10 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | |||||
| CVSS 3.1 | CRITICAL | MITRE-CVE | ||||
| CVSS 3.1 | CRITICAL | [email protected] |
Solution
- Update SiYuan to version 3.7.0 or later.
- Review and sanitize CSS snippets from untrusted sources.
- Disable snippet syncing if updates are not immediate.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-54067.
| URL | Resource |
|---|---|
| https://github.com/siyuan-note/siyuan/security/advisories/GHSA-mvjr-vv3c-w4qv | |
| https://github.com/siyuan-note/siyuan/security/advisories/GHSA-mvjr-vv3c-w4qv |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-54067 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-54067
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-54067 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-54067 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
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CVE Translated by [email protected]
Oct. 25, 2026
Action Type Old Value New Value Added Translation Title: siyuan de siyuan-note, Description: SiYuan es un sistema de gestión de conocimiento personal de código abierto. Antes de la versión 3.7.0, el cuerpo de un fragmento CSS que contiene [/style] se escapa de su etiqueta [style] circundante cuando renderSnippet() lo interpola a través de insertAdjacentHTML. Una carga útil como ejecuta JavaScript arbitrario en el renderizador. En las compilaciones de escritorio de Electron, el renderizador se ejecuta con nodeIntegration:true, por lo que require(’child_process’) es accesible desde el gestor inyectado y el XSS se encadena a RCE del host. Los fragmentos se sincronizan a través del repositorio del espacio de trabajo, por lo que un atacante con acceso de escritura a cualquier espacio de trabajo sincronizado implanta la carga útil una vez y se activa en cada dispositivo que la descarga. El error también omite la separación enabledCSS / enabledJS del usuario. Un usuario que desactivó enabledJS estaba tomando una decisión deliberada de no ejecutar JavaScript no confiable; la ruta CSS lo ejecuta de todos modos. Esta vulnerabilidad está corregida en la versión 3.7.0. -
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Jun. 25, 2026
Action Type Old Value New Value Added Reference https://github.com/siyuan-note/siyuan/security/advisories/GHSA-mvjr-vv3c-w4qv Added SSVC {'id': 'CVE-2026-54067', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'poc'}, {'automatable': 'no'}, {'technicalImpact': 'total'}], 'version': '2.0.3', 'timestamp': '2026-06-25T15:29:14.922467Z'} -
New CVE Received by [email protected]
Jun. 24, 2026
Action Type Old Value New Value Added Affected [{'vendor': 'siyuan-note', 'product': 'siyuan', 'versions': [{'status': 'affected', 'version': '< 3.7.0'}]}] Added Description SiYuan is an open-source personal knowledge management system. Prior to 3.7.0, CSS snippet body containing </style> breaks out of its surrounding <style> tag when renderSnippet() interpolates it via insertAdjacentHTML. A payload like runs arbitrary JavaScript in the renderer. On Electron desktop builds the renderer runs with nodeIntegration:true, so require('child_process') is reachable from the injected handler and the XSS chains to host RCE. Snippets sync via the workspace repository, so an attacker with write access to any synced workspace plants the payload once and it fires on every device that pulls. The bug also bypasses the user's enabledCSS / enabledJS separation. A user who turned enabledJS off was making a deliberate call not to run untrusted JavaScript; the CSS path runs it anyway. This vulnerability is fixed in 3.7.0. Added CVSS V3.1 AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H Added CWE CWE-79 Added CWE CWE-1188 Added Reference https://github.com/siyuan-note/siyuan/security/advisories/GHSA-mvjr-vv3c-w4qv