CVE-2026-66396

HIGHPre-NVD 8.48.4—
EchelonGraph scoreMEDIUM confidence

Score 8.4 from GitHub Security Advisory (severity: CRITICAL) published 2026-07-27. a secondary CVSS source baseline 8.4; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, secondary
Trending — 3 sources updated this weekElevated
8.4EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 8.4Exploit: Elevated riskExposed: 0

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

SiYuan before v3.7.2 fails to escape the title-img Individual Attribute List value when rendering Gallery and Kanban cover images, allowing stored cross-site scripting via unescaped style attribute interpolation. Attackers with editor permissions can inject onload handlers that execute arbitrary code in the Electron renderer with full Node.js access when victims open affected documents.

CVSS v3
8.4
EG Score
8.4(medium)
EG Risk
54(Track*)
EG Risk 54/100SSVC: 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
Severity84% × 45%
Exploitation40% × 40%
Automatability0% × 15%
Action: Watch closely — could escalate to Attend.
EPSS PROB
0%
EPSS %ILE
22%
KEV
Not listed

Published

July 27, 2026

Last Modified

July 28, 2026

Advisory Details (2)

Auto-updated Jul 27, 2026
🔬 Proof of concept available. Patch available. Sources: github.
generic

SiYuan before v3.7.2 Stored XSS to RCE via title-img IAL | Advisories | VulnCheck

https://www.vulncheck.com/advisories/siyuan-before-stored-xss-to-rce-via-title-img-ial
github Patch Available🟡 PoC Available

Stored XSS to OS RCE via `title-img` IAL attribute unescaped into `style="..."` on the AV Gallery and Kanban cover `<img>` · Advisory · siyuan-note/siyuan · GitHub

https://github.com/siyuan-note/siyuan/security/advisories/GHSA-5rxg-wh59-mg34

Vendor Advisories for CVE-2026-66396(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 21× in last 7d / 109× 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 129 total refreshes for this CVE.

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

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-66396?
CVE-2026-66396 is a high vulnerability published on July 27, 2026. SiYuan before v3.7.2 fails to escape the title-img Individual Attribute List value when rendering Gallery and Kanban cover images, allowing stored cross-site scripting via unescaped style attribute interpolation. Attackers with editor permissions can inject onload handlers that execute arbitrary…
When was CVE-2026-66396 disclosed?
CVE-2026-66396 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-2026-66396 actively exploited?
CVE-2026-66396 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 78.3% of all scored CVEs.
What is the CVSS score of CVE-2026-66396?
CVE-2026-66396 has a CVSS v3 base score of 8.4 (NVD).
How do I remediate CVE-2026-66396?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-66396, 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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