CVE-2021-27903

CRITICALNVD 9.89.8—
EchelonGraph scoreMEDIUM confidence

This critical-severity CVE scores 9.8 under NVD CVSS v3. EPSS exploit probability: 2.8%, top 15% 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
9.8EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 3%CVSS: 9.8Exploit: None knownExposed: 0

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

An issue was discovered in Craft CMS before 3.6.7. In some circumstances, a potential Remote Code Execution vulnerability existed on sites that did not restrict administrative changes (if an attacker were somehow able to hijack an administrator's session).

CVSS v3
9.8
EG Score
9.8(medium)
EG Risk
50(Track)
EG Risk 50/100SSVC: 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
Severity98% × 45%
Exploitation3% × 40%
Automatability30% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
3%
EPSS %ILE
86%
KEV
Not listed

Published

June 30, 2021

Last Modified

November 21, 2024

Advisory Details (3)

Auto-updated Sep 19, 2026
Patch available. Sources: github_commit.
github_commit Patch Available

commit c17728fa0bec (craftcms/cms)

Patch available: craftcms/cms 5.10.8 (contains commit c17728fa0bec)

https://github.com/craftcms/cms/commit/c17728fa0bec11d3b82c34defe0930ed409aec38
generic

cms/CHANGELOG.md at 5.x · craftcms/cms · GitHub

https://github.com/craftcms/cms/blob/develop/CHANGELOG.md#security
generic

cms/CHANGELOG.md at 5.x · craftcms/cms · GitHub

https://github.com/craftcms/cms/blob/develop/CHANGELOG.md#367---2021-02-23

Affected Packages

(1 across 1 ecosystem)
Packagist(1)
PackageVulnerable rangeFixed inDependents
craftcms/cms1.0.26.1 ... 3.6.6 (686 versions)3.6.7—

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 8× in last 7d / 32× 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 158 total refreshes for this CVE.

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

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2021-27903?
CVE-2021-27903 is a critical vulnerability published on June 30, 2021. An issue was discovered in Craft CMS before 3.6.7. In some circumstances, a potential Remote Code Execution vulnerability existed on sites that did not restrict administrative changes (if an attacker were somehow able to hijack an administrator's session).
When was CVE-2021-27903 disclosed?
CVE-2021-27903 was first published in the National Vulnerability Database on June 30, 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-2021-27903 actively exploited?
CVE-2021-27903 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 3% probability of exploitation in the next 30 days, which ranks it in the top 14.1% of all scored CVEs.
What is the CVSS score of CVE-2021-27903?
CVE-2021-27903 has a CVSS v3 base score of 9.8 (NVD).
How do I remediate CVE-2021-27903?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2021-27903, 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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