CVE-2026-91021

MEDIUMPre-NVD 5.45.4—
EchelonGraph scoreHIGH confidence

Score 5.4 from GitHub Security Advisory published 2026-09-14. CISA-ADP (Vulnrichment) CVSS v3.1 baseline 5.4; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: cisa-adp, epss, ghsa
Trending — 3 sources updated this week
5.4EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 5.4Exploit: None knownExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

Trilium Notes, version v0.103.0 and earlier, contains a stored cross-site scripting (XSS) vulnerability in the share renderer for webView notes due to improper HTML escaping of user-controlled #webViewSrc values. This vulnerability allows attackers with note-authoring privileges to inject arbitrary JavaScript that executes for any user who opens the shared note, including administrators.

CVSS v3
5.4
EG Score
5.4(high)
EG Risk
24(Track)
EG Risk 24/100SSVC: Track

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
Severity54% × 45%
Exploitation0% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
12%
KEV
Not listed

Published

September 14, 2026

Last Modified

September 16, 2026

References (1)

Vendor Advisories for CVE-2026-91021(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 19× in last 7d / 36× 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. 2026-09-24 22:12 UTCEG score recompute
  2. 2026-09-24 22:12 UTCGHSA enrichment
  3. 2026-09-24 14:04 UTCEPSS rescore
  4. 2026-09-23 21:12 UTCEG score recompute
  5. 2026-09-23 21:12 UTCGHSA enrichment
  6. 2026-09-23 17:54 UTCEPSS rescore
  7. 2026-09-22 20:11 UTCEG score recompute
  8. 2026-09-22 20:11 UTCGHSA enrichment
  9. 2026-09-22 16:01 UTCEPSS rescore
  10. 2026-09-21 21:09 UTCEPSS rescore
  11. 2026-09-21 19:11 UTCEG score recompute
  12. 2026-09-21 19:11 UTCGHSA enrichment
  13. 2026-09-20 20:16 UTCEPSS rescore
  14. 2026-09-20 18:10 UTCGHSA enrichment
  15. 2026-09-19 17:10 UTCEG score recompute
  16. 2026-09-19 17:10 UTCGHSA enrichment
  17. 2026-09-18 19:28 UTCEPSS rescore
  18. 2026-09-18 16:10 UTCEG score recompute
  19. 2026-09-18 16:09 UTCGHSA enrichment
  20. 2026-09-17 19:32 UTCEPSS rescore
  21. 2026-09-17 14:46 UTCEG score recompute
  22. 2026-09-17 14:45 UTCGHSA enrichment
  23. 2026-09-16 14:09 UTCEPSS rescore
  24. 2026-09-16 13:45 UTCEG score recompute
  25. 2026-09-16 13:44 UTCGHSA enrichment
Show 11 more
  1. 2026-09-16 05:15 UTCEPSS rescore
  2. 2026-09-15 21:24 UTCEG score recompute
  3. 2026-09-15 21:24 UTCGHSA enrichment
  4. 2026-09-14 20:23 UTCGHSA enrichment
  5. 2026-09-14 19:49 UTCEG score recompute▲ 5.40
  6. 2026-09-14 19:49 UTCGHSA enrichment
  7. 2026-09-14 19:49 UTCMITRE cvelistV5CVSS v3 → 5.4 · severity → MEDIUM
  8. 2026-09-14 18:31 UTCGHSA enrichment
  9. 2026-09-14 18:29 UTCNVD update
  10. 2026-09-14 17:21 UTCEG score recompute
  11. 2026-09-14 17:21 UTCMITRE cvelistV5first tracked

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-91021?
CVE-2026-91021 is a medium vulnerability published on September 14, 2026. Trilium Notes, version v0.103.0 and earlier, contains a stored cross-site scripting (XSS) vulnerability in the share renderer for webView notes due to improper HTML escaping of user-controlled #webViewSrc values. This vulnerability allows attackers with note-authoring privileges to inject arbitrary…
When was CVE-2026-91021 disclosed?
CVE-2026-91021 was first published in the National Vulnerability Database on September 14, 2026, with the most recent update on September 16, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-91021 actively exploited?
CVE-2026-91021 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0% probability of exploitation in the next 30 days, which ranks it in the top 88.2% of all scored CVEs.
What is the CVSS score of CVE-2026-91021?
CVE-2026-91021 has a CVSS v3.1 base score of 5.4 (CISA-ADP / Vulnrichment enrichment; NVD's own analysis pending).
How do I remediate CVE-2026-91021?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-91021, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

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