CVE-2026-28377

HIGHPre-NVD 7.57.5
EchelonGraph scoreMEDIUM confidence

This high-severity CVE scores 7.5 under the CNA's CVSS (NVD's own analysis pending). EPSS exploit probability: 0.2%, top 95% 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: cna:grafana, epss
7.5EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 7.5Exploit: None knownExposed: 0

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

A vulnerability in Grafana Tempo exposes the S3 SSE-C encryption key in plaintext through the /status/config endpoint, potentially allowing unauthorized users to obtain the key used to encrypt trace data stored in S3.

Thanks to william_goodfellow for reporting this vulnerability.

CVSS v3
7.5
EG Score
7.5(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
Severity75% × 45%
Exploitation0% × 40%
Automatability100% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
5%
KEV
Not listed

Published

March 26, 2026

Last Modified

August 26, 2026

Advisory Details (1)

Auto-updated Jul 7, 2026
No patch confirmed yet.
generic

S3 SSE-C Encryption Key Exposed in Plaintext via Config Endpoint | Grafana Labs

https://grafana.com/security/security-advisories/cve-2026-28377

Vendor Advisories for CVE-2026-28377(1)

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

Affected Packages

(1 across 1 ecosystem)
Go(1)
PackageVulnerable rangeFixed inDependents
github.com/grafana/tempo2.10.3

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 8× in last 7d / 44× 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 111 total refreshes for this CVE.

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

Frequently asked(5)

What is CVE-2026-28377?
CVE-2026-28377 is a high vulnerability published on March 26, 2026. A vulnerability in Grafana Tempo exposes the S3 SSE-C encryption key in plaintext through the /status/config endpoint, potentially allowing unauthorized users to obtain the key used to encrypt trace data stored in S3. Thanks to william_goodfellow for reporting this vulnerability.
When was CVE-2026-28377 disclosed?
CVE-2026-28377 was first published in the National Vulnerability Database on March 26, 2026, with the most recent update on August 26, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-28377 actively exploited?
CVE-2026-28377 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 95.1% of all scored CVEs.
What is the CVSS score of CVE-2026-28377?
CVE-2026-28377 has a CVSS v4.0 base score of 7.5 (CNA self-assessment; NVD's own analysis pending).
How do I remediate CVE-2026-28377?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-28377, 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

See which npm, PyPI, Go, and Maven packages are affected by CVE-2026-28377

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