CVE-2026-100641SiYuan before v3.8.4 Stored XSS via Unescaped Flashcard Content
Updated under an hour ago ()
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It affects siyuan-note siyuan. Add what you run to find out whether that includes you.
EPSS puts the chance of exploitation in the next 30 days at 0.53%, higher than 43% of scored CVEs.
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SiYuan before v3.8.4 does not HTML-escape stored flashcard block content before interpolating it into the card-manager list markup. Block content returned by /api/riff/getRiffCards is inserted into a card item template in app/src/card/viewCards.ts and assigned to listElement.innerHTML, so content such as <img src=invalid onerror=...> becomes an executable event-handler attribute. Because the SiYuan desktop (Electron) main window is created with nodeIntegration enabled and contextIsolation disabled, an administrator who opens the card manager on a workspace containing attacker-supplied flashcard content (for example introduced through contribution or import) executes the attacker's script in a privileged renderer, which can lead to arbitrary code execution on the host. The affected endpoint remains behind authentication and administrator-role checks; this is an untrusted-content-to-privileged-renderer issue, not an authorization bypass.
- CVSS
- 8.0 HIGH (v3.1, CNA)CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H
- Weakness (CWE)
- CWE-79
- Known exploited
- Not in CISA's KEV catalog
- EPSS (exploitation in the next 30 days)
- 0.53% (percentile 43)
- Assigned by
- VulnCheck
- NVD analysis
- Deferred
- Record last updated
- Oct 5, 2026
- First seen by InfoSec Signals
- Oct 9, 2026
Affected products
siyuan-note siyuan siyuan_note:siyuan (from the name) | before 3.8.4; 3.8.4 not affected | CNA record |
References
- https://github.com/siyuan-note/siyuan/security/advisories/GHSA-2mmf-4xwm-55rmvendor-advisory
- https://github.com/siyuan-note/siyuan/commit/1ecb1c07de497ff03b585536fe5579291754d96bpatch
- https://github.com/siyuan-note/siyuan/commit/48c354e7de130aaada9d7120125bbc768344fd3bpatch
- https://github.com/siyuan-note/siyuan/commit/41b14025b4ac4a8379d1200580344ca18ad152b7patch
- https://github.com/siyuan-note/siyuan/commit/8641553a1f07374001902d3ce773285db1292b2dpatch
- https://www.vulncheck.com/advisories/siyuan-before-3.8.4-stored-xss-via-unescaped-flashcard-contentthird-party-advisory
The CVE record on cve.org NVD's entry
The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.