CVE-2026-100639
published 2026-09-26CVE-2026-100639: SiYuan v3.8.3 fails to HTML-escape the data-subtype attribute when generating gutter-button markup (app/src/protyle/gutter/button.ts, assigned via innerHTML in…
PriorityP350high8.8CVSS 3.1
AVNACLPRNUIRSUCHIHAH
EPSS
0.47%
38.8th percentile
SiYuan v3.8.3 fails to HTML-escape the data-subtype attribute when generating gutter-button markup (app/src/protyle/gutter/button.ts, assigned via innerHTML in app/src/protyle/gutter/index.ts) from content pasted as plain-text Markdown containing a Kramdown inline attribute list (IAL). Because the shared Lute renderer parses Kramdown IAL from text/plain input, an attacker-supplied Markdown snippet using entity-encoded quotes in data-subtype breaks out of the attribute value when the gutter markup is re-parsed by the browser, injecting additional attributes such as autofocus and onfocus. If a victim pastes the crafted Markdown and the affected gutter control receives focus, the injected handler executes; in the Electron desktop application, where the main BrowserWindow enables Node integration and disables context isolation, this results in JavaScript execution with renderer Node.js privileges (remote code execution). Fixed in v3.8.4.
Affected
1 ranges
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| siyuan-note | siyuan | < 3.8.4 | 3.8.4 |
CVSS provenance
nvdv3.18.8HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
nvdv4.08.6HIGHCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
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GHSA
SiYuan v3.8.3 fails to HTML-escape the data-subtype attribute when generating gutter-button markup (app/src/protyle/gutter/button.ts, assigned via innerHTML in app/src/protyle/gutter/index.ts) from co
ghsa_unreviewed·2026-09-26
CVE-2026-100639 [HIGH] CWE-79 SiYuan v3.8.3 fails to HTML-escape the data-subtype attribute when generating gutter-button markup (app/src/protyle/gutter/button.ts, assigned via innerHTML in app/src/protyle/gutter/index.ts) from co
SiYuan v3.8.3 fails to HTML-escape the data-subtype attribute when generating gutter-button markup (app/src/protyle/gutter/button.ts, assigned via innerHTML in app/src/protyle/gutter/index.ts) from content pasted as plain-text Markdown containing a Kramdown inline attribute list (IAL). Because the shared Lute renderer parses Kramdown IAL from text/plain input, an attacker-supplied Markdown snippet using entity-encoded quotes in data-subtype breaks out of the attribute value when the gutter markup is re-parsed by the browser, injecting additional attributes such as autofocus and onfocus. If a victim pastes the crafted Markdown and the affected gutter control receives focus, the injected handler executes; in the Electron desktop application, where the main BrowserWindow enables Node integrat
VulDB
siyuan-note SiYuan up to 3.8.3 Gutter Button button.ts innerHTML data-subtype cross site scripting
vuldb·2026-09-26·CVSS 8.8
CVE-2026-100639 [HIGH] siyuan-note SiYuan up to 3.8.3 Gutter Button button.ts innerHTML data-subtype cross site scripting
A vulnerability was found in siyuan-note SiYuan up to 3.8.3 and classified as problematic. The affected element is the function innerHTML of the file app/src/protyle/gutter/button.ts of the component Gutter Button. Executing a manipulation of the argument data-subtype can lead to cross site scripting.
This vulnerability is registered as CVE-2026-100639. It is possible to launch the attack remotely. No exploit is available.
It is suggested to upgrade the affected component.
No detection rules found.
No public exploits indexed.
No writeups or analysis indexed.
2026-09-26
Published