CVE-2026-33540

HIGHNVD 7.57.5—
EchelonGraph scoreMEDIUM confidence

This high-severity CVE scores 7.5 under NVD CVSS v3. EPSS exploit probability: 0.3%, top 80% 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
Elevated
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: Elevated riskExposed: 0

A fix is available — apply it.

Distribution is a toolkit to pack, ship, store, and deliver container content. Prior to 3.1.0, in pull-through cache mode, distribution discovers token auth endpoints by parsing WWW-Authenticate challenges returned by the configured upstream registry. The realm URL from a bearer challenge is used without validating that it matches the upstream registry host. As a result, an attacker-controlled upstream (or an attacker with MitM position to the upstream) can cause distribution to send the configured upstream credentials via basic auth to an attacker-controlled realm URL. This vulnerability is fixed in 3.1.0.

CVSS v3
7.5
EG Score
7.5(medium)
EG Risk
65(Attend)
EG Risk 65/100SSVC: Attend

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%
Exploitation40% × 40%
Automatability100% × 15%
Action: Remediate soon — notable exploitation risk.
EPSS PROB
0%
EPSS %ILE
20%
KEV
Not listed

Published

April 6, 2026

Last Modified

April 9, 2026

Advisory Details (1)

Auto-updated Aug 2, 2026
🔬 Proof of concept available. Patch available. Sources: github.
github Patch Available🟡 PoC Available

Pull-through cache credential exfiltration via www-authenticate bearer realm · Advisory · distribution/distribution · GitHub

https://github.com/distribution/distribution/security/advisories/GHSA-3p65-76g6-3w7r

Vendor Advisories for CVE-2026-33540(1)

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

Patch Availability(1)

Vendor / EcosystemFixed in / PatchReleasedSource
redhatodf4/rook-ceph-rhel9-operator:17829342842026-07-09redhat

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

(6 across 5 ecosystems)
Go(2)
PackageVulnerable rangeFixed inDependents
github.com/distribution/distribution———
github.com/distribution/distribution/v3—3.1.0—
Debian:11(1)
PackageVulnerable rangeFixed inDependents
docker-registry2.7.1+ds2-7 ... 2.8.3+ds1-3 (12 versions)——
Debian:12(1)
PackageVulnerable rangeFixed inDependents
docker-registry2.8.2+ds1-1, 2.8.3+ds1-1, 2.8.3+ds1-2, 2.8.3+ds1-3——
Debian:13(1)
PackageVulnerable rangeFixed inDependents
docker-registry2.8.3+ds1-2, 2.8.3+ds1-3——
Debian:14(1)
PackageVulnerable rangeFixed inDependents
docker-registry2.8.3+ds1-22.8.3+ds1-3—

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 7× in last 7d / 33× 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 180 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. 2026-09-06 13:47 UTCEPSS rescore
  11. 2026-09-04 05:06 UTCEPSS rescore
  12. 2026-09-02 14:11 UTCEPSS rescore
  13. 2026-09-02 09:44 UTCOSV refresh
  14. 2026-09-01 13:53 UTCEPSS rescore
  15. 2026-09-01 04:39 UTCEPSS rescore
  16. 2026-09-01 04:39 UTCEPSS rescore
  17. 2026-08-30 19:17 UTCEPSS rescore
  18. 2026-08-30 01:22 UTCEPSS rescore
  19. 2026-08-28 21:41 UTCEPSS rescore
  20. 2026-08-27 14:25 UTCEPSS rescore
  21. 2026-08-26 14:46 UTCEPSS rescore
  22. 2026-08-25 13:49 UTCEPSS rescore
  23. 2026-08-24 14:17 UTCEPSS rescore
  24. 2026-08-23 00:19 UTCEPSS rescore
  25. 2026-08-21 23:49 UTCEPSS rescore
Show 75 more
  1. 2026-08-20 22:55 UTCEPSS rescore
  2. 2026-08-20 22:55 UTCEPSS rescore
  3. 2026-08-19 17:03 UTCEPSS rescore
  4. 2026-08-18 13:48 UTCEPSS rescore
  5. 2026-08-17 13:47 UTCEPSS rescore
  6. 2026-08-16 14:56 UTCEPSS rescore
  7. 2026-08-16 08:26 UTCEG score recompute
  8. 2026-08-16 08:26 UTCVendor advisory
  9. 2026-08-16 02:14 UTCEPSS rescore
  10. 2026-08-15 01:30 UTCEPSS rescore
  11. 2026-08-14 18:47 UTCVendor advisory
  12. 2026-08-14 05:34 UTCEG score recompute
  13. 2026-08-14 05:34 UTCVendor advisory
  14. 2026-08-13 22:00 UTCEPSS rescore
  15. 2026-08-13 09:45 UTCVendor advisory
  16. 2026-08-12 19:48 UTCEG score recompute
  17. 2026-08-12 19:48 UTCVendor advisory
  18. 2026-08-12 13:50 UTCEPSS rescore
  19. 2026-08-11 20:09 UTCEG score recompute
  20. 2026-08-11 20:09 UTCVendor advisory
  21. 2026-08-11 03:19 UTCEG score recompute
  22. 2026-08-11 03:19 UTCVendor advisory
  23. 2026-08-11 00:00 UTCEPSS rescore
  24. 2026-08-10 03:12 UTCVendor advisory
  25. 2026-08-09 16:08 UTCEG score recompute
  26. 2026-08-09 16:08 UTCVendor advisory
  27. 2026-08-09 13:46 UTCEPSS rescore
  28. 2026-08-09 05:04 UTCEG score recompute
  29. 2026-08-09 05:04 UTCVendor advisory
  30. 2026-08-08 16:37 UTCEPSS rescore
  31. 2026-08-08 02:13 UTCEG score recompute
  32. 2026-08-08 02:13 UTCVendor advisory
  33. 2026-08-07 15:10 UTCEG score recompute
  34. 2026-08-07 15:10 UTCVendor advisory
  35. 2026-08-06 13:46 UTCEPSS rescore
  36. 2026-08-06 13:04 UTCVendor advisory
  37. 2026-08-06 00:09 UTCEG score recompute
  38. 2026-08-06 00:09 UTCVendor advisory
  39. 2026-08-05 19:17 UTCEPSS rescore
  40. 2026-08-04 15:10 UTCEPSS rescore
  41. 2026-08-04 10:38 UTCEPSS rescore
  42. 2026-08-03 22:30 UTCEG score recompute
  43. 2026-08-03 22:30 UTCVendor advisory
  44. 2026-08-03 10:36 UTCEPSS rescore
  45. 2026-08-03 01:30 UTCVendor advisory
  46. 2026-08-02 14:26 UTCEG score recompute
  47. 2026-08-02 14:26 UTCVendor advisory
  48. 2026-08-02 02:27 UTCEPSS rescore
  49. 2026-08-01 04:16 UTCEPSS rescore
  50. 2026-07-30 16:28 UTCEPSS rescore
  51. 2026-07-30 01:30 UTCEPSS rescore
  52. 2026-07-27 14:13 UTCEPSS rescore
  53. 2026-07-26 14:54 UTCEPSS rescore
  54. 2026-07-26 14:54 UTCEPSS rescore
  55. 2026-07-25 14:18 UTCEPSS rescore
  56. 2026-07-25 14:18 UTCEPSS rescore
  57. 2026-07-24 14:17 UTCEPSS rescore
  58. 2026-07-24 14:17 UTCEPSS rescore
  59. 2026-07-23 14:18 UTCEPSS rescore
  60. 2026-07-23 14:18 UTCEPSS rescore
  61. 2026-07-23 03:09 UTCEG score recompute
  62. 2026-07-22 14:08 UTCEPSS rescore
  63. 2026-07-21 15:24 UTCEPSS rescore
  64. 2026-07-20 17:08 UTCEPSS rescore
  65. 2026-07-19 14:31 UTCEPSS rescore
  66. 2026-07-19 02:29 UTCEPSS rescore
  67. 2026-07-18 10:04 UTCEPSS rescore
  68. 2026-07-17 02:24 UTCOSV refresh
  69. 2026-07-16 17:03 UTCEPSS rescore
  70. 2026-07-15 16:57 UTCEPSS rescore
  71. 2026-07-15 16:57 UTCEPSS rescore
  72. 2026-07-15 02:00 UTCEPSS rescore
  73. 2026-07-13 22:30 UTCEPSS rescore
  74. 2026-07-13 06:13 UTCEPSS rescore
  75. 2026-07-13 06:13 UTCEPSS rescore

Frequently asked(5)

What is CVE-2026-33540?
CVE-2026-33540 is a high vulnerability published on April 6, 2026. Distribution is a toolkit to pack, ship, store, and deliver container content. Prior to 3.1.0, in pull-through cache mode, distribution discovers token auth endpoints by parsing WWW-Authenticate challenges returned by the configured upstream registry. The realm URL from a bearer challenge is used…
When was CVE-2026-33540 disclosed?
CVE-2026-33540 was first published in the National Vulnerability Database on April 6, 2026, with the most recent update on April 9, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-33540 actively exploited?
CVE-2026-33540 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 80.3% of all scored CVEs.
What is the CVSS score of CVE-2026-33540?
CVE-2026-33540 has a CVSS v3 base score of 7.5 (NVD).
How do I remediate CVE-2026-33540?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-33540, 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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