CVE-2010-4021

NONECVSS 0.0
0.0
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • No confirmed exploitation signals yet
CISA-KEV: Not listedEPSS: 2%CVSS: —Exploit: NoneExposed: 0

A fix is available — apply it.

The Key Distribution Center (KDC) in MIT Kerberos 5 (aka krb5) 1.7 does not properly restrict the use of TGT credentials for armoring TGS requests, which might allow remote authenticated users to impersonate a client by rewriting an inner request, aka a "KrbFastReq forgery issue."

CVSS v3
—
EG Score
0.0(none)
EPSS
79.4%
KEV
Not listed

Published

December 2, 2010

Last Modified

April 29, 2026

References (34)

Patch Availability(1)

Vendor / EcosystemFixed in / PatchReleasedSource
ubuntulibkrb5-3 (1.7dfsg~beta3-1ubuntu0.7) @ karmic2026-05-29ubuntu

Patches are aggregated from vendor advisories (Red Hat, Microsoft, Cisco, GitHub) and package ecosystems (OSV, GHSA). Multiple rows for the same upstream release have been deduplicated.

All Vendor Advisories

(1)

Every vendor that published an advisory referencing this CVE — pulled from our cve_vendor_advisories aggregation. Click any row for the vendor's original advisory page.

Data Freshness Timeline

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

Frequently asked(4)

What is CVE-2010-4021?
CVE-2010-4021 is a none vulnerability published on December 2, 2010. The Key Distribution Center (KDC) in MIT Kerberos 5 (aka krb5) 1.7 does not properly restrict the use of TGT credentials for armoring TGS requests, which might allow remote authenticated users to impersonate a client by rewriting an inner request, aka a "KrbFastReq forgery issue."
When was CVE-2010-4021 disclosed?
CVE-2010-4021 was first published in the National Vulnerability Database on December 2, 2010, with the most recent update on April 29, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2010-4021 actively exploited?
CVE-2010-4021 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 79.4% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
How do I remediate CVE-2010-4021?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2010-4021, 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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