CVE-2026-5366

CRITICALPre-NVD 9.99.9—
EchelonGraph scoreMEDIUM confidence

Score 9.9 from GitHub Security Advisory (severity: CRITICAL) published 2026-06-20. a secondary CVSS source baseline 9.9; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, secondary
Trending — 3 sources updated this week
9.9EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 1%CVSS: 9.9Exploit: None knownExposed: 0

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

Prefect version 3.6.23 is vulnerable to remote code execution due to improper handling of user-controlled input in the GitRepository storage class. The commit_sha parameter, which is passed to git commands, lacks validation and does not include a -- separator to distinguish user input from git flags. This allows attackers to inject arbitrary git flags, such as --upload-pack, enabling execution of external programs. Additionally, the directories parameter can be exploited to inject git flags during sparse-checkout operations. These vulnerabilities allow any user with deployment creation permissions to execute arbitrary commands on worker machines, compromising shared work pools in multi-tenant environments.

CVSS v3
9.9
EG Score
9.9(medium)
EG Risk
49(Track)
EG Risk 49/100SSVC: 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
Severity99% × 45%
Exploitation1% × 40%
Automatability30% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
1%
EPSS %ILE
61%
KEV
Not listed

Published

June 20, 2026

Last Modified

July 1, 2026

Advisory Details (1)

Auto-updated Aug 29, 2026
No patch confirmed yet.
generic

huntr - The world's first bug bounty platform for AI/ML

https://huntr.com/bounties/e2e88a0f-a8f6-49c9-94c5-e98dc385f07a

Vendor Advisories for CVE-2026-5366(1)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 10× in last 7d / 163× 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 430 total refreshes for this CVE.

  1. 2026-09-01 13:54 UTCEPSS rescore
  2. 2026-09-01 04:40 UTCEPSS rescore
  3. 2026-08-31 00:32 UTCGHSA enrichment
  4. 2026-08-30 20:44 UTCEG score recompute
  5. 2026-08-30 20:43 UTCGHSA enrichment
  6. 2026-08-30 19:17 UTCEPSS rescore
  7. 2026-08-30 01:22 UTCEPSS rescore
  8. 2026-08-28 21:42 UTCEPSS rescore
  9. 2026-08-27 14:25 UTCEPSS rescore
  10. 2026-08-26 14:46 UTCEPSS rescore
  11. 2026-08-25 13:49 UTCEPSS rescore
  12. 2026-08-25 05:52 UTCGHSA enrichment
  13. 2026-08-25 02:04 UTCGHSA enrichment
  14. 2026-08-24 22:16 UTCEG score recompute
  15. 2026-08-24 22:16 UTCGHSA enrichment
  16. 2026-08-24 13:57 UTCEG score recompute
  17. 2026-08-24 13:57 UTCGHSA enrichment
  18. 2026-08-24 04:59 UTCGHSA enrichment
  19. 2026-08-23 23:16 UTCGHSA enrichment
  20. 2026-08-23 19:23 UTCGHSA enrichment
  21. 2026-08-23 15:33 UTCGHSA enrichment
  22. 2026-08-23 11:44 UTCGHSA enrichment
  23. 2026-08-23 07:54 UTCGHSA enrichment
  24. 2026-08-23 03:33 UTCEG score recompute
  25. 2026-08-23 03:33 UTCGHSA enrichment
Show 75 more
  1. 2026-08-23 00:19 UTCEPSS rescore
  2. 2026-08-22 23:01 UTCGHSA enrichment
  3. 2026-08-22 01:13 UTCEG score recompute
  4. 2026-08-22 01:13 UTCGHSA enrichment
  5. 2026-08-21 23:49 UTCEPSS rescore
  6. 2026-08-21 21:23 UTCGHSA enrichment
  7. 2026-08-21 17:35 UTCGHSA enrichment
  8. 2026-08-21 13:14 UTCGHSA enrichment
  9. 2026-08-21 09:26 UTCGHSA enrichment
  10. 2026-08-21 05:23 UTCGHSA enrichment
  11. 2026-08-20 23:53 UTCEG score recompute
  12. 2026-08-20 23:53 UTCGHSA enrichment
  13. 2026-08-20 22:55 UTCEPSS rescore
  14. 2026-08-20 20:03 UTCGHSA enrichment
  15. 2026-08-20 16:15 UTCGHSA enrichment
  16. 2026-08-20 12:23 UTCGHSA enrichment
  17. 2026-08-20 07:54 UTCEG score recompute
  18. 2026-08-20 07:54 UTCGHSA enrichment
  19. 2026-08-19 17:04 UTCEPSS rescore
  20. 2026-08-19 14:53 UTCGHSA enrichment
  21. 2026-08-19 11:01 UTCGHSA enrichment
  22. 2026-08-19 05:49 UTCEG score recompute
  23. 2026-08-19 05:49 UTCGHSA enrichment
  24. 2026-08-18 13:48 UTCEPSS rescore
  25. 2026-08-17 15:27 UTCGHSA enrichment
  26. 2026-08-17 11:34 UTCGHSA enrichment
  27. 2026-08-17 07:44 UTCGHSA enrichment
  28. 2026-08-17 03:56 UTCGHSA enrichment
  29. 2026-08-17 00:08 UTCGHSA enrichment
  30. 2026-08-16 20:19 UTCGHSA enrichment
  31. 2026-08-16 15:57 UTCEG score recompute
  32. 2026-08-16 15:57 UTCGHSA enrichment
  33. 2026-08-16 14:56 UTCEPSS rescore
  34. 2026-08-16 12:08 UTCGHSA enrichment
  35. 2026-08-16 08:20 UTCGHSA enrichment
  36. 2026-08-16 04:31 UTCEG score recompute
  37. 2026-08-16 04:31 UTCGHSA enrichment
  38. 2026-08-16 00:43 UTCGHSA enrichment
  39. 2026-08-15 20:55 UTCGHSA enrichment
  40. 2026-08-15 16:50 UTCGHSA enrichment
  41. 2026-08-15 13:02 UTCGHSA enrichment
  42. 2026-08-15 09:06 UTCGHSA enrichment
  43. 2026-08-15 05:17 UTCEG score recompute
  44. 2026-08-15 05:17 UTCGHSA enrichment
  45. 2026-08-15 01:30 UTCEPSS rescore
  46. 2026-08-15 01:28 UTCGHSA enrichment
  47. 2026-08-14 21:40 UTCGHSA enrichment
  48. 2026-08-14 17:52 UTCGHSA enrichment
  49. 2026-08-14 13:45 UTCGHSA enrichment
  50. 2026-08-14 09:57 UTCGHSA enrichment
  51. 2026-08-14 06:09 UTCGHSA enrichment
  52. 2026-08-14 02:20 UTCGHSA enrichment
  53. 2026-08-13 22:32 UTCEG score recompute
  54. 2026-08-13 22:32 UTCGHSA enrichment
  55. 2026-08-13 22:00 UTCEPSS rescore
  56. 2026-08-13 18:44 UTCGHSA enrichment
  57. 2026-08-13 14:10 UTCGHSA enrichment
  58. 2026-08-13 10:11 UTCGHSA enrichment
  59. 2026-08-13 06:22 UTCGHSA enrichment
  60. 2026-08-13 02:33 UTCGHSA enrichment
  61. 2026-08-12 22:45 UTCGHSA enrichment
  62. 2026-08-12 18:57 UTCGHSA enrichment
  63. 2026-08-12 15:09 UTCEG score recompute
  64. 2026-08-12 15:09 UTCGHSA enrichment
  65. 2026-08-12 13:51 UTCEPSS rescore
  66. 2026-08-12 11:21 UTCGHSA enrichment
  67. 2026-08-12 07:32 UTCGHSA enrichment
  68. 2026-08-12 03:44 UTCGHSA enrichment
  69. 2026-08-11 23:55 UTCGHSA enrichment
  70. 2026-08-11 20:07 UTCGHSA enrichment
  71. 2026-08-11 16:19 UTCEG score recompute
  72. 2026-08-11 16:19 UTCGHSA enrichment
  73. 2026-08-11 12:30 UTCGHSA enrichment
  74. 2026-08-11 08:38 UTCGHSA enrichment
  75. 2026-08-11 04:50 UTCGHSA enrichment

Frequently asked(5)

What is CVE-2026-5366?
CVE-2026-5366 is a critical vulnerability published on June 20, 2026. Prefect version 3.6.23 is vulnerable to remote code execution due to improper handling of user-controlled input in the GitRepository storage class. The commit_sha parameter, which is passed to git commands, lacks validation and does not include a -- separator to distinguish user input from git…
When was CVE-2026-5366 disclosed?
CVE-2026-5366 was first published in the National Vulnerability Database on June 20, 2026, with the most recent update on July 1, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-5366 actively exploited?
CVE-2026-5366 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 1% probability of exploitation in the next 30 days, which ranks it in the top 38.5% of all scored CVEs.
What is the CVSS score of CVE-2026-5366?
CVE-2026-5366 has a CVSS v3 base score of 9.9 (NVD).
How do I remediate CVE-2026-5366?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-5366, 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

Explore the affected products and dependency analysis for CVE-2026-5366

Explore →

Is Your Infrastructure Affected by CVE-2026-5366?

EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.

Start Free Scan →Browse All CVEs