CVE-2021-42146

HIGHNVD 7.57.5—
EchelonGraph scoreMEDIUM confidence

Score 7.5 from GitHub Security Advisory (severity: HIGH) published 2024-01-24. NVD baseline CVSS 7.5; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, nvd
7.5
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS: 1%CVSS: 7.5Exploit: NoneExposed: 0

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

An issue was discovered in Contiki-NG tinyDTLS through master branch 53a0d97. DTLS servers allow remote attackers to reuse the same epoch number within two times the TCP maximum segment lifetime, which is prohibited in RFC6347. This vulnerability allows remote attackers to obtain sensitive application (data of connected clients).

CVSS v3
7.5
EG Score
7.5(medium)
EPSS
47.3%
KEV
Not listed

Published

January 24, 2024

Last Modified

June 20, 2025

References (3)

Weakness Classification(2)

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

Data Freshness Timeline

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

Frequently asked(5)

What is CVE-2021-42146?
CVE-2021-42146 is a high vulnerability published on January 24, 2024. An issue was discovered in Contiki-NG tinyDTLS through master branch 53a0d97. DTLS servers allow remote attackers to reuse the same epoch number within two times the TCP maximum segment lifetime, which is prohibited in RFC6347. This vulnerability allows remote attackers to obtain sensitive…
When was CVE-2021-42146 disclosed?
CVE-2021-42146 was first published in the National Vulnerability Database on January 24, 2024, with the most recent update on June 20, 2025. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2021-42146 actively exploited?
CVE-2021-42146 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 47.3% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2021-42146?
CVE-2021-42146 has a CVSS v3 base score of 7.5 (NVD).
How do I remediate CVE-2021-42146?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2021-42146, 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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