CVE-2026-40937

HIGHNVD 8.38.3—
EchelonGraph scoreMEDIUM confidence

Score 8.3 from GitHub Security Advisory (severity: HIGH) published 2026-04-22. NVD baseline CVSS 8.3; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, nvd
8.3EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 8.3Exploit: None knownExposed: 0

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

RustFS is a distributed object storage system built in Rust. Prior to 1.0.0-alpha.94, all four notification target admin API endpoints in rustfs/src/admin/handlers/event.rs use a check_permissions helper that validates authentication only (access key + session token), without performing any admin-action authorization via validate_admin_request. Every other admin handler in the codebase correctly calls validate_admin_request with a specific AdminAction. This is the only admin handler file that skips authorization. A non-admin user can overwrite a shared admin-defined notification target by name, causing subsequent bucket events to be delivered to an attacker-controlled endpoint. This enables cross-user event interception and audit evasion. 1.0.0-alpha.94 contains a patch.

CVSS v3
8.3
EG Score
8.3(medium)
EG Risk
37(Track)
EG Risk 37/100SSVC: 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
Severity83% × 45%
Exploitation0% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
22%
KEV
Not listed

Published

April 22, 2026

Last Modified

April 24, 2026

Advisory Details (2)

Auto-updated May 4, 2026
🔬 Proof of concept available. Patch available. Sources: github.
github Patch Available🟡 PoC Available

Missing admin authorization on notification target endpoints allows unauthenticated configuration of event webhooks · Advisory · rustfs/rustfs · GitHub

https://github.com/rustfs/rustfs/security/advisories/GHSA-pfcq-4gjr-6gjm
generic

Release 1.0.0-alpha.94 · rustfs/rustfs · GitHub

https://github.com/rustfs/rustfs/releases/tag/1.0.0-alpha.94

Patch Availability(1)

Vendor / EcosystemFixed in / PatchReleasedSource
rustrustfs—ghsa

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.

Affected Packages

(1 across 1 ecosystem)
crates.io(1)
PackageVulnerable rangeFixed inDependents
rustfs———

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 7× in last 7d / 27× 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 190 total refreshes for this CVE.

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

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rust:rustfs

Frequently asked(5)

What is CVE-2026-40937?
CVE-2026-40937 is a high vulnerability published on April 22, 2026. RustFS is a distributed object storage system built in Rust. Prior to 1.0.0-alpha.94, all four notification target admin API endpoints in rustfs/src/admin/handlers/event.rs use a checkpermissions helper that validates authentication only (access key + session token), without performing any…
When was CVE-2026-40937 disclosed?
CVE-2026-40937 was first published in the National Vulnerability Database on April 22, 2026, with the most recent update on April 24, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-40937 actively exploited?
CVE-2026-40937 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0% probability of exploitation in the next 30 days, which ranks it in the top 78.3% of all scored CVEs.
What is the CVSS score of CVE-2026-40937?
CVE-2026-40937 has a CVSS v3 base score of 8.3 (NVD).
How do I remediate CVE-2026-40937?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-40937, 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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