CVE-2026-75916

SiYuan XSS-to-RCE via unescaped block metadata in hint popup

HIGH
8.6
CVSS Score
Published: August 19, 2026 at 02:01 PM UTC
Updated: October 8, 2026 at 04:17 PM UTC
2 products affected across 2 vendorsSiyuanSiyuan

Using siyuan by siyuan-note?

Get instant alerts when new vulnerabilities affect siyuan - before attackers find them.

Real-time alertsTrack your software stackFree plan available
Severity
HIGH8.6
Exploit prediction
EPSS 0.2%
SSVC
PoC

Description

SiYuan through 3.7.3 contains a cross-site scripting vulnerability in the '((' block-reference autocomplete hint popup. In genHintItemHTML() (app/src/protyle/hint/extend.ts), a candidate block's name, alias, and memo fields are concatenated into the popup's HTML without escaping. An attacker who can set these metadata fields on a block can inject a self-firing payload (e.g. <img src=x onerror=...>) that executes automatically when a victim types '((' followed by a search term that surfaces the crafted block. Because SiYuan's Electron windows run with nodeIntegration enabled, contextIsolation disabled, and no CSP, the injected script gains require('child_process') access, allowing the XSS to escalate to arbitrary OS command execution.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

All versions
All versions

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

SSVC — Action Prioritization

SSVCPoCNot automatableTotal impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

8.6HIGHVulnCheck
Attack Vector
LOCAL
Complexity
LOW
Privileges
NONE
User Interaction
REQUIRED
Scope
CHANGED
Confidentiality
HIGH
Integrity
HIGH
Availability
HIGH
Vector?

Quick Info

StatusDEFERRED
CWE
CWE-79

Get alerted

Stop reading CVE feeds looking for your own stack

Track the products you run and VulnTracker tells you when a new CVE affects them — with what is known about fixing it, and nothing about the rest.

Free plan, no card