CVE-2026-100643

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 weekElevated
8.0EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0.4%CVSS: 8.0Exploit: Elevated riskExposed services: Not assessed

A fix is available — apply it.

SiYuan versions before v3.8.4 fail to properly escape four stored Attribute View values in textarea elements, allowing authenticated attackers to inject JavaScript by modifying field descriptions, template sources, select option descriptions, or footer calculation templates. Attackers can execute stored JavaScript when other users open affected database menus, and in the Electron desktop app with nodeIntegration enabled, this leads to command execution with SiYuan process privileges.

CVSS v3
8.0
EG Score
8.0HIGHhigh confidence
EG Risk
52
EG Risk 52/100CISA 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%
Exploitation40% × 40%
Automatability0% × 15%
CISA SSVC: Track at low, Track* at medium and Attend at high mission impact.
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
0.4%
EPSS %ILE
34th
KEV
Not listed

CISA SSVCTrack at low, Track* at medium and Attend at high mission impact.

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

Exploitation public PoC (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact total (CISA Vulnrichment). 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 28, 2026

Advisory Details (2)

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

SiYuan before v3.8.4 Stored XSS via Attribute View textarea | Advisories | VulnCheck

https://www.vulncheck.com/advisories/siyuan-before-3.8.4-stored-xss-via-attribute-view-textarea
github Patch Available🟡 PoC Available

Incomplete fix for GHSA-gcm3-qcq3-72rv leaves stored XSS in Attribute View textarea editors · Advisory · siyuan-note/siyuan · GitHub

https://github.com/siyuan-note/siyuan/security/advisories/GHSA-h3p6-c22r-fx2j

Vendor Advisories for CVE-2026-100643(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 30× in last 7d / 35× 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 04:56 UTCGHSA enrichment
  2. 2026-10-03 16:19 UTCEG score recompute
  3. 2026-10-03 16:19 UTCGHSA enrichment
  4. 2026-10-03 14:25 UTCEPSS rescore
  5. 2026-10-03 03:42 UTCEG score recompute
  6. 2026-10-03 03:42 UTCGHSA enrichment
  7. 2026-10-02 15:01 UTCGHSA enrichment
  8. 2026-10-02 02:23 UTCEG score recompute
  9. 2026-10-02 02:23 UTCGHSA enrichment
  10. 2026-10-01 19:49 UTCEPSS rescore
  11. 2026-10-01 13:42 UTCGHSA enrichment
  12. 2026-10-01 01:04 UTCEG score recompute
  13. 2026-10-01 01:04 UTCGHSA enrichment
  14. 2026-09-30 15:02 UTCEPSS rescore
  15. 2026-09-30 12:26 UTCGHSA enrichment
  16. 2026-09-29 23:48 UTCEG score recompute
  17. 2026-09-29 23:48 UTCGHSA enrichment
  18. 2026-09-29 15:20 UTCEPSS rescore
  19. 2026-09-29 08:11 UTCEG score recompute
  20. 2026-09-29 08:11 UTCGHSA enrichment
  21. 2026-09-28 19:30 UTCEG score recompute
  22. 2026-09-28 19:30 UTCGHSA enrichment
  23. 2026-09-28 18:52 UTCEG score recompute
  24. 2026-09-28 18:52 UTCGHSA enrichment
  25. 2026-09-28 17:06 UTCEG score recompute
Show 10 more
  1. 2026-09-28 17:06 UTCGHSA enrichment
  2. 2026-09-28 13:50 UTCEPSS rescore
  3. 2026-09-28 04:28 UTCGHSA enrichment
  4. 2026-09-27 15:51 UTCEG score recompute
  5. 2026-09-27 15:50 UTCGHSA enrichment
  6. 2026-09-27 03:12 UTCEG score recompute
  7. 2026-09-27 03:12 UTCGHSA enrichment
  8. 2026-09-26 14:34 UTCEG score recompute
  9. 2026-09-26 13:39 UTCEG score recompute
  10. 2026-09-26 13:30 UTCMITRE cvelistV5first tracked

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-100643?
CVE-2026-100643 is a high vulnerability published on September 26, 2026. SiYuan versions before v3.8.4 fail to properly escape four stored Attribute View values in textarea elements, allowing authenticated attackers to inject JavaScript by modifying field descriptions, template sources, select option descriptions, or footer calculation templates. Attackers can execute…
When was CVE-2026-100643 disclosed?
CVE-2026-100643 was first published on September 26, 2026, with the most recent update on September 28, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-100643 actively exploited?
CVE-2026-100643 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.4% probability of exploitation in the next 30 days (34th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-100643?
CVE-2026-100643 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-2026-100643?
A fix for CVE-2026-100643 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-100643 are linked in the Vendor Advisories panel on this page.

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