CVE-2026-66395

CRITICALPre-NVD 9.69.6—
EchelonGraph scoreMEDIUM confidence

Score 9.6 from GitHub Security Advisory (severity: CRITICAL) published 2026-07-27. a secondary CVSS source baseline 9.6; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, secondary
Trending — 3 sources updated this weekElevated
9.6EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 9.6Exploit: Elevated riskExposed: 0

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

SiYuan desktop before v3.7.2 contains a reflected cross-site scripting vulnerability in the bazaar plugin readme handler that allows attackers to execute arbitrary code by crafting a malicious siyuan:// deep link. Attackers can inject HTML payloads via the plugin name parameter that execute with full Node.js access through insertAdjacentHTML rendering in an insecurely configured Electron renderer.

CVSS v3
9.6
EG Score
9.6(medium)
EG Risk
59(Track*)
EG Risk 59/100SSVC: 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
Severity96% × 45%
Exploitation40% × 40%
Automatability0% × 15%
Action: Watch closely — could escalate to Attend.
EPSS PROB
0%
EPSS %ILE
25%
KEV
Not listed

Published

July 27, 2026

Last Modified

July 28, 2026

Advisory Details (2)

Auto-updated Aug 23, 2026
🔬 Proof of concept available. Patch available. Sources: github.
github Patch Available🟡 PoC Available

Reflected XSS to OS RCE in the SiYuan desktop via `siyuan://` deep link · Advisory · siyuan-note/siyuan · GitHub

https://github.com/siyuan-note/siyuan/security/advisories/GHSA-6gx2-8gcr-x83f
generic

SiYuan Desktop before v3.7.2 Reflected XSS to RCE via siyuan Protocol | Advisories | VulnCheck

https://www.vulncheck.com/advisories/siyuan-desktop-before-reflected-xss-to-rce-via-siyuan-protocol

Vendor Advisories for CVE-2026-66395(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 42× in last 7d / 219× 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.

Showing the most recent 100 of 253 total refreshes for this CVE.

  1. 2026-08-30 07:57 UTCGHSA enrichment
  2. 2026-08-30 03:51 UTCEG score recompute
  3. 2026-08-30 03:51 UTCGHSA enrichment
  4. 2026-08-30 01:22 UTCEPSS rescore
  5. 2026-08-29 23:52 UTCEG score recompute
  6. 2026-08-29 23:52 UTCGHSA enrichment
  7. 2026-08-28 21:42 UTCEPSS rescore
  8. 2026-08-28 01:27 UTCGHSA enrichment
  9. 2026-08-27 20:59 UTCEG score recompute
  10. 2026-08-27 20:59 UTCGHSA enrichment
  11. 2026-08-27 13:42 UTCGHSA enrichment
  12. 2026-08-27 09:43 UTCGHSA enrichment
  13. 2026-08-27 03:43 UTCGHSA enrichment
  14. 2026-08-26 23:44 UTCGHSA enrichment
  15. 2026-08-26 19:44 UTCEG score recompute
  16. 2026-08-26 19:44 UTCGHSA enrichment
  17. 2026-08-26 14:53 UTCEG score recompute
  18. 2026-08-26 14:53 UTCGHSA enrichment
  19. 2026-08-26 14:47 UTCEPSS rescore
  20. 2026-08-26 10:52 UTCGHSA enrichment
  21. 2026-08-26 06:50 UTCGHSA enrichment
  22. 2026-08-26 02:09 UTCGHSA enrichment
  23. 2026-08-25 22:10 UTCGHSA enrichment
  24. 2026-08-25 17:59 UTCGHSA enrichment
  25. 2026-08-25 13:58 UTCEG score recompute
Show 75 more
  1. 2026-08-25 13:57 UTCGHSA enrichment
  2. 2026-08-25 13:49 UTCEPSS rescore
  3. 2026-08-25 09:58 UTCGHSA enrichment
  4. 2026-08-25 05:58 UTCGHSA enrichment
  5. 2026-08-25 01:57 UTCGHSA enrichment
  6. 2026-08-24 21:58 UTCGHSA enrichment
  7. 2026-08-24 17:59 UTCEG score recompute
  8. 2026-08-24 17:59 UTCGHSA enrichment
  9. 2026-08-24 12:43 UTCEG score recompute
  10. 2026-08-24 12:43 UTCGHSA enrichment
  11. 2026-08-24 08:43 UTCGHSA enrichment
  12. 2026-08-24 04:15 UTCGHSA enrichment
  13. 2026-08-24 00:15 UTCGHSA enrichment
  14. 2026-08-23 20:16 UTCGHSA enrichment
  15. 2026-08-23 16:16 UTCGHSA enrichment
  16. 2026-08-23 12:10 UTCGHSA enrichment
  17. 2026-08-23 08:11 UTCGHSA enrichment
  18. 2026-08-23 04:11 UTCEG score recompute
  19. 2026-08-23 04:11 UTCGHSA enrichment
  20. 2026-08-23 00:19 UTCEPSS rescore
  21. 2026-08-23 00:11 UTCGHSA enrichment
  22. 2026-08-22 20:10 UTCGHSA enrichment
  23. 2026-08-22 16:10 UTCGHSA enrichment
  24. 2026-08-22 12:11 UTCGHSA enrichment
  25. 2026-08-22 08:12 UTCGHSA enrichment
  26. 2026-08-22 04:12 UTCGHSA enrichment
  27. 2026-08-22 00:12 UTCEG score recompute
  28. 2026-08-22 00:12 UTCGHSA enrichment
  29. 2026-08-21 23:49 UTCEPSS rescore
  30. 2026-08-21 20:12 UTCGHSA enrichment
  31. 2026-08-21 16:12 UTCGHSA enrichment
  32. 2026-08-21 12:11 UTCGHSA enrichment
  33. 2026-08-21 08:11 UTCGHSA enrichment
  34. 2026-08-21 04:11 UTCGHSA enrichment
  35. 2026-08-21 00:12 UTCEG score recompute
  36. 2026-08-21 00:12 UTCGHSA enrichment
  37. 2026-08-20 22:56 UTCEPSS rescore
  38. 2026-08-20 20:12 UTCGHSA enrichment
  39. 2026-08-20 16:12 UTCGHSA enrichment
  40. 2026-08-20 12:10 UTCGHSA enrichment
  41. 2026-08-20 07:56 UTCGHSA enrichment
  42. 2026-08-20 03:57 UTCGHSA enrichment
  43. 2026-08-19 23:57 UTCGHSA enrichment
  44. 2026-08-19 19:57 UTCEG score recompute
  45. 2026-08-19 19:57 UTCGHSA enrichment
  46. 2026-08-19 17:04 UTCEPSS rescore
  47. 2026-08-19 15:39 UTCGHSA enrichment
  48. 2026-08-19 11:39 UTCGHSA enrichment
  49. 2026-08-19 07:34 UTCGHSA enrichment
  50. 2026-08-19 03:34 UTCGHSA enrichment
  51. 2026-08-18 22:49 UTCGHSA enrichment
  52. 2026-08-18 18:46 UTCEG score recompute
  53. 2026-08-18 18:46 UTCGHSA enrichment
  54. 2026-08-18 13:48 UTCEPSS rescore
  55. 2026-08-18 09:32 UTCGHSA enrichment
  56. 2026-08-18 05:33 UTCGHSA enrichment
  57. 2026-08-18 01:24 UTCGHSA enrichment
  58. 2026-08-17 20:15 UTCEG score recompute
  59. 2026-08-17 20:15 UTCGHSA enrichment
  60. 2026-08-17 13:47 UTCEPSS rescore
  61. 2026-08-17 13:46 UTCGHSA enrichment
  62. 2026-08-17 09:47 UTCGHSA enrichment
  63. 2026-08-17 05:48 UTCGHSA enrichment
  64. 2026-08-17 01:41 UTCGHSA enrichment
  65. 2026-08-16 21:42 UTCGHSA enrichment
  66. 2026-08-16 17:43 UTCEG score recompute
  67. 2026-08-16 17:43 UTCGHSA enrichment
  68. 2026-08-16 14:56 UTCEPSS rescore
  69. 2026-08-16 13:41 UTCGHSA enrichment
  70. 2026-08-16 09:41 UTCGHSA enrichment
  71. 2026-08-16 05:42 UTCEG score recompute
  72. 2026-08-16 05:42 UTCGHSA enrichment
  73. 2026-08-16 01:43 UTCGHSA enrichment
  74. 2026-08-15 21:44 UTCGHSA enrichment
  75. 2026-08-15 17:45 UTCGHSA enrichment

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-66395?
CVE-2026-66395 is a critical vulnerability published on July 27, 2026. SiYuan desktop before v3.7.2 contains a reflected cross-site scripting vulnerability in the bazaar plugin readme handler that allows attackers to execute arbitrary code by crafting a malicious siyuan:// deep link. Attackers can inject HTML payloads via the plugin name parameter that execute with…
When was CVE-2026-66395 disclosed?
CVE-2026-66395 was first published in the National Vulnerability Database on July 27, 2026, with the most recent update on July 28, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-66395 actively exploited?
CVE-2026-66395 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 74.9% of all scored CVEs.
What is the CVSS score of CVE-2026-66395?
CVE-2026-66395 has a CVSS v3 base score of 9.6 (NVD).
How do I remediate CVE-2026-66395?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-66395, 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.

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