CVE-2026-40262

HIGHNVD 8.78.7—
EchelonGraph scoreMEDIUM confidence

This high-severity CVE scores 8.7 under NVD CVSS v3. EPSS exploit probability: 0.0%, top 98% of all CVEs by exploit prediction. GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).

Triggered by: NVD CVSS baseline
Sources: epss, nvd
Elevated
8.7
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS: 0%CVSS: 8.7Exploit: NoneExposed: 0

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

Note Mark is an open-source note-taking application. In versions 0.19.1 and prior, the asset delivery handler serves uploaded files inline and relies on magic-byte detection for content type, which does not identify text-based formats such as HTML, SVG, or XHTML. These files are served with an empty Content-Type, no X-Content-Type-Options: nosniff header, and inline disposition, allowing browsers to sniff and render active content. An authenticated user can upload an HTML or SVG file containing JavaScript as a note asset, and when a victim navigates to the asset URL, the script executes under the application's origin with access to the victim's authenticated session and API actions. This issue has been fixed in version 0.19.2.

CVSS v3
8.7
EG Score
8.7(medium)
EPSS
22.7%
KEV
Not listed

Published

April 17, 2026

Last Modified

April 17, 2026

Advisory Details (3)

Auto-updated Jun 3, 2026
🔬 Proof of concept available. Patch available. Sources: github_commit, github_release, github.
github Patch Available🟡 PoC Available

Stored XSS via Unrestricted Asset Upload · Advisory · enchant97/note-mark · GitHub

https://github.com/enchant97/note-mark/security/advisories/GHSA-9pr4-rf97-79qh
github_release Patch Available

V0.19.2

Patch available: enchant97/note-mark v0.19.2

https://github.com/enchant97/note-mark/releases/tag/v0.19.2
github_commit Patch Available

commit 6bb62842ccb9 (enchant97/note-mark)

Patch available: enchant97/note-mark v0.19.2 (contains commit 6bb62842ccb9)

https://github.com/enchant97/note-mark/commit/6bb62842ccb956870b9bf183629eba95e326e5e3

Affected Packages

(1 across 1 ecosystem)
Go(1)
PackageVulnerable rangeFixed inDependents
github.com/enchant97/note-mark/backend—0.0.0-20260411145018-6bb62842ccb9—

Weakness Classification(2)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

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

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-40262?
CVE-2026-40262 is a high vulnerability published on April 17, 2026. Note Mark is an open-source note-taking application. In versions 0.19.1 and prior, the asset delivery handler serves uploaded files inline and relies on magic-byte detection for content type, which does not identify text-based formats such as HTML, SVG, or XHTML. These files are served with an…
When was CVE-2026-40262 disclosed?
CVE-2026-40262 was first published in the National Vulnerability Database on April 17, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-40262 actively exploited?
CVE-2026-40262 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 22.7% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2026-40262?
CVE-2026-40262 has a CVSS v3 base score of 8.7 (NVD).
How do I remediate CVE-2026-40262?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-40262, 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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