CVE-2021-43853

HIGHNVD 8.78.7—
EchelonGraph scoreMEDIUM confidence

This high-severity CVE scores 8.7 under NVD CVSS v3. EPSS exploit probability: 0.2%, top 53% 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
8.7
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS: 1%CVSS: 8.7Exploit: NoneExposed: 0

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

Ajax.NET Professional (AjaxPro) is an AJAX framework available for Microsoft ASP.NET. Affected versions of this package are vulnerable to JavaScript object injection which may result in cross site scripting when leveraged by a malicious user. The affected core relates to JavaScript object creation when parsing json input. Releases before version 21.12.22.1 are affected. A workaround exists that replaces one of the core JavaScript files embedded in the library. See the GHSA-5q7q-qqw2-hjq7 for workaround details.

CVSS v3
8.7
EG Score
8.7(medium)
EPSS
53.1%
KEV
Not listed

Published

December 22, 2021

Last Modified

November 21, 2024

References (6)

Affected Packages

(1 across 1 ecosystem)
NuGet(1)
PackageVulnerable rangeFixed inDependents
AjaxNetProfessional21.10.30, 21.11.22, 21.11.29, 21.12.21.1, 21.12.8.121.12.22.1—

Weakness Classification(2)

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

Data Freshness Timeline

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

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2021-43853?
CVE-2021-43853 is a high vulnerability published on December 22, 2021. Ajax.NET Professional (AjaxPro) is an AJAX framework available for Microsoft ASP.NET. Affected versions of this package are vulnerable to JavaScript object injection which may result in cross site scripting when leveraged by a malicious user. The affected core relates to JavaScript object creation…
When was CVE-2021-43853 disclosed?
CVE-2021-43853 was first published in the National Vulnerability Database on December 22, 2021, with the most recent update on November 21, 2024. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2021-43853 actively exploited?
CVE-2021-43853 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 53.1% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2021-43853?
CVE-2021-43853 has a CVSS v3 base score of 8.7 (NVD).
How do I remediate CVE-2021-43853?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2021-43853, 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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