CVE-2026-74234

HIGHPre-NVD 7.77.7—
EchelonGraph scoreHIGH confidence

Score 7.7 from GitHub Security Advisory published 2026-08-17. a secondary CVSS source baseline 7.7; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, secondary
Trending — 4 sources updated this week
7.7EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 7.7Exploit: None knownExposed: 0

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

Legora before 2026-08-14 contains a cross-site scripting vulnerability that allows attackers to achieve arbitrary JavaScript execution in a victim's browser by embedding a Mermaid block prefixed with a gray-matter JavaScript front-matter directive, causing the front-matter parser to invoke eval() before any SVG sanitization occurs. Attackers can exploit this flaw through influenced Mermaid diagram content to execute arbitrary JavaScript in the user's browser context, with elevated impact on Word and Outlook add-in surfaces where bearer session tokens are persisted in localStorage.

CVSS v3
7.7
EG Score
7.7(high)
EG Risk
39(Track)
EG Risk 39/100SSVC: 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
Severity77% × 45%
Exploitation0% × 40%
Automatability30% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
21%
KEV
Not listed

Published

August 17, 2026

Last Modified

August 17, 2026

Advisory Details (2)

Auto-updated Aug 17, 2026
No patch confirmed yet.
generic

Legora < 2026-08-14 XSS via Mermaid gray-matter JavaScript Engine | Advisories | VulnCheck

https://www.vulncheck.com/advisories/legora-2026-08-14-xss-via-mermaid-gray-matter-javascript-engine
generic

Legora

https://legora.com/

Vendor Advisories for CVE-2026-74234(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 17× in last 7d / 17× 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. 2026-08-21 03:23 UTCEG score recompute
  2. 2026-08-21 03:23 UTCGHSA enrichment
  3. 2026-08-20 22:56 UTCEPSS rescore
  4. 2026-08-20 14:15 UTCGHSA enrichment
  5. 2026-08-20 01:03 UTCEG score recompute
  6. 2026-08-20 01:03 UTCGHSA enrichment
  7. 2026-08-19 17:04 UTCEPSS rescore
  8. 2026-08-19 11:54 UTCGHSA enrichment
  9. 2026-08-18 22:46 UTCEG score recompute
  10. 2026-08-18 22:46 UTCGHSA enrichment
  11. 2026-08-18 13:49 UTCEPSS rescore
  12. 2026-08-18 13:49 UTCEPSS rescore
  13. 2026-08-18 09:36 UTCEG score recompute
  14. 2026-08-18 09:36 UTCGHSA enrichment
  15. 2026-08-17 20:29 UTCEG score recompute
  16. 2026-08-17 19:50 UTCEG score recompute
  17. 2026-08-17 19:49 UTCMITRE cvelistV5first tracked

Frequently asked(5)

What is CVE-2026-74234?
CVE-2026-74234 is a high vulnerability published on August 17, 2026. Legora before 2026-08-14 contains a cross-site scripting vulnerability that allows attackers to achieve arbitrary JavaScript execution in a victim's browser by embedding a Mermaid block prefixed with a gray-matter JavaScript front-matter directive, causing the front-matter parser to invoke eval()…
When was CVE-2026-74234 disclosed?
CVE-2026-74234 was first published in the National Vulnerability Database on August 17, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-74234 actively exploited?
CVE-2026-74234 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 79.4% of all scored CVEs.
What is the CVSS score of CVE-2026-74234?
CVE-2026-74234 has a CVSS v3 base score of 7.7 (NVD).
How do I remediate CVE-2026-74234?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-74234, 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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