CVE-2026-100641

HIGHPre-NVD 8.08.0—
EchelonGraph scoreHIGH confidence

Score 8.0 from GitHub Security Advisory (severity: HIGH) published 2026-09-26. A secondary CVSS source baseline 8.0; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, secondary
Trending — 3 sources updated this week
8.0EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0.5%CVSS: 8.0Exploit: None knownExposed services: Not assessed

A fix is available — apply it.

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 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 v3
8.0
EG Score
8.0HIGHhigh confidence
EG Risk
41
EG Risk 41/100CISA SSVC

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity80% × 45%
Exploitation1% × 40%
Automatability30% × 15%
CISA SSVC: Track at low or medium mission impact; Track or Attend at high (mission-essential systems).
Action: A fix is available. Apply it within your standard update timelines at low or medium mission impact and sooner than that at high.
EPSS PROB
0.5%
EPSS %ILE
42nd
KEV
Not listed

CISA SSVCTrack at low or medium mission impact; Track or Attend at high (mission-essential systems).

A fix is available. Apply it within your standard update timelines at low or medium mission impact and sooner than that at high.

Exploitation none (no KEV listing, exploit record or EPSS ≥ 50%) · Automatable unknown (not published for this CVE) · Technical impact partial (CVSS below 9.0). Mission impact is CISA's Mission & Well-being decision point, and only you can judge it: high means the affected system is essential to your organisation's mission, or its compromise could cause irreversible harm to people. CISA's decision table

Published

September 26, 2026

Last Modified

September 26, 2026

Advisory Details (6)

Auto-updated Sep 26, 2026
🔬 Proof of concept available. Patch available. Sources: github_commit, github.
generic

SiYuan before v3.8.4 Stored XSS via Unescaped Flashcard Content | Advisories | VulnCheck

https://www.vulncheck.com/advisories/siyuan-before-3.8.4-stored-xss-via-unescaped-flashcard-content
github_commit

commit 8641553a1f07 (siyuan-note/siyuan)

Fix landed in siyuan-note/siyuan commit 8641553a1f07 — awaiting tagged release

https://github.com/siyuan-note/siyuan/commit/8641553a1f07374001902d3ce773285db1292b2d
github_commit

commit 41b14025b4ac (siyuan-note/siyuan)

Fix landed in siyuan-note/siyuan commit 41b14025b4ac — awaiting tagged release

https://github.com/siyuan-note/siyuan/commit/41b14025b4ac4a8379d1200580344ca18ad152b7
github_commit

commit 48c354e7de13 (siyuan-note/siyuan)

Fix landed in siyuan-note/siyuan commit 48c354e7de13 — awaiting tagged release

https://github.com/siyuan-note/siyuan/commit/48c354e7de130aaada9d7120125bbc768344fd3b
github_commit

commit 1ecb1c07de49 (siyuan-note/siyuan)

Fix landed in siyuan-note/siyuan commit 1ecb1c07de49 — awaiting tagged release

https://github.com/siyuan-note/siyuan/commit/1ecb1c07de497ff03b585536fe5579291754d96b
github Patch Available🟡 PoC Available

Unescaped Flashcard Content Enables Code Execution in the Desktop Card Manager · Advisory · siyuan-note/siyuan · GitHub

https://github.com/siyuan-note/siyuan/security/advisories/GHSA-2mmf-4xwm-55rm

Vendor Advisories for CVE-2026-100641(1)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 27× in last 7d / 32× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

  1. 2026-10-04 10:22 UTCGHSA enrichment
  2. 2026-10-03 21:55 UTCEG score recompute
  3. 2026-10-03 21:55 UTCGHSA enrichment
  4. 2026-10-03 14:25 UTCEPSS rescore
  5. 2026-10-03 09:19 UTCGHSA enrichment
  6. 2026-10-02 20:51 UTCEG score recompute
  7. 2026-10-02 20:51 UTCGHSA enrichment
  8. 2026-10-02 08:24 UTCGHSA enrichment
  9. 2026-10-01 19:58 UTCEG score recompute
  10. 2026-10-01 19:58 UTCGHSA enrichment
  11. 2026-10-01 19:49 UTCEPSS rescore
  12. 2026-10-01 07:32 UTCGHSA enrichment
  13. 2026-09-30 19:06 UTCEG score recompute
  14. 2026-09-30 19:06 UTCGHSA enrichment
  15. 2026-09-30 15:02 UTCEPSS rescore
  16. 2026-09-30 06:40 UTCGHSA enrichment
  17. 2026-09-29 18:14 UTCEG score recompute
  18. 2026-09-29 18:14 UTCGHSA enrichment
  19. 2026-09-29 15:20 UTCEPSS rescore
  20. 2026-09-29 04:51 UTCEG score recompute
  21. 2026-09-29 04:51 UTCGHSA enrichment
  22. 2026-09-28 16:25 UTCEG score recompute
  23. 2026-09-28 16:25 UTCGHSA enrichment
  24. 2026-09-28 13:50 UTCEPSS rescore
  25. 2026-09-28 03:58 UTCGHSA enrichment
Show 7 more
  1. 2026-09-27 15:32 UTCEG score recompute
  2. 2026-09-27 15:31 UTCGHSA enrichment
  3. 2026-09-27 03:02 UTCEG score recompute
  4. 2026-09-27 03:01 UTCGHSA enrichment
  5. 2026-09-26 14:35 UTCEG score recompute
  6. 2026-09-26 13:39 UTCEG score recompute
  7. 2026-09-26 13:30 UTCMITRE cvelistV5first tracked

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-100641?
CVE-2026-100641 is a high vulnerability published on September 26, 2026. 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…
When was CVE-2026-100641 disclosed?
CVE-2026-100641 was first published on September 26, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-100641 actively exploited?
CVE-2026-100641 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.5% probability of exploitation in the next 30 days (42nd percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-100641?
CVE-2026-100641 has a CVSS base score of 8.0 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-100641?
A fix for CVE-2026-100641 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-100641 are linked in the Vendor Advisories panel on this page.

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