CVE-2026-6826

MEDIUMNVD 5.35.3—
EchelonGraph scoreMEDIUM confidence

Score 5.3 from GitHub Security Advisory published 2026-05-21. NVD baseline CVSS 5.3; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, nvd
5.3
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS: 0%CVSS: 5.3Exploit: NoneExposed: 0

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

Concrete CMS 9.5.0 and below  is vulnerable to unauthenticated file usage disclosure via missing permission check in the usage controller.  Any unauthenticated visitor can request /ccm/system/dialogs/file/usage/{fID} with any file ID and receive a list of every page that references that file, including page IDs, handles, and full URLs. This includes pages that are otherwise restricted by permissions.The Concrete CMS security team gave this vulnerability a CVSS v.4.0 score of 6.9 with vector CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N. Thanks Eldudareeno for reporting.

CVSS v3
5.3
EG Score
5.3(medium)
EPSS
16.3%
KEV
Not listed

Published

May 21, 2026

Last Modified

May 26, 2026

Advisory Details (1)

Auto-updated Jun 17, 2026
No patch confirmed yet.
generic

9.5.1 Release Notes :: Concrete CMS

https://documentation.concretecms.org/9-x/developers/introduction/version-history/951-release-notes

Vendor Advisories for CVE-2026-6826(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 / 51× 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 112 total refreshes for this CVE.

  1. 2026-07-15 16:57 UTCEPSS rescore
  2. 2026-07-15 02:00 UTCEPSS rescore
  3. 2026-07-13 22:31 UTCEPSS rescore
  4. 2026-07-13 06:13 UTCEPSS rescore
  5. 2026-07-13 06:13 UTCEPSS rescore
  6. 2026-07-12 05:46 UTCEPSS rescore
  7. 2026-07-11 08:27 UTCEPSS rescore
  8. 2026-07-11 08:27 UTCEPSS rescore
  9. 2026-07-09 19:10 UTCEPSS rescore
  10. 2026-07-09 19:10 UTCEPSS rescore
  11. 2026-07-08 15:16 UTCEPSS rescore
  12. 2026-07-08 15:16 UTCEPSS rescore
  13. 2026-07-07 13:46 UTCEPSS rescore
  14. 2026-07-07 13:46 UTCEPSS rescore
  15. 2026-07-06 16:27 UTCEPSS rescore
  16. 2026-07-06 16:27 UTCEPSS rescore
  17. 2026-07-06 02:23 UTCEPSS rescore
  18. 2026-07-06 02:23 UTCEPSS rescore
  19. 2026-07-05 02:31 UTCEPSS rescore
  20. 2026-07-05 02:30 UTCEPSS rescore
  21. 2026-07-04 06:31 UTCEPSS rescore
  22. 2026-07-04 06:31 UTCEPSS rescore
  23. 2026-07-01 15:07 UTCEPSS rescore
  24. 2026-06-30 23:22 UTCEPSS rescore
  25. 2026-06-29 19:55 UTCEG score recompute
Show 75 more
  1. 2026-06-29 14:06 UTCEPSS rescore
  2. 2026-06-28 14:07 UTCEPSS rescore
  3. 2026-06-28 04:56 UTCEPSS rescore
  4. 2026-06-27 21:02 UTCEG score recompute
  5. 2026-06-27 03:08 UTCEPSS rescore
  6. 2026-06-26 19:20 UTCEG score recompute
  7. 2026-06-25 14:14 UTCEG score recompute
  8. 2026-06-25 13:50 UTCEPSS rescore
  9. 2026-06-24 14:05 UTCEPSS rescore
  10. 2026-06-23 21:33 UTCEPSS rescore
  11. 2026-06-22 14:25 UTCEPSS rescore
  12. 2026-06-22 14:25 UTCEPSS rescore
  13. 2026-06-21 14:56 UTCEPSS rescore
  14. 2026-06-21 14:56 UTCEPSS rescore
  15. 2026-06-21 01:59 UTCEPSS rescore
  16. 2026-06-21 01:59 UTCEPSS rescore
  17. 2026-06-19 19:26 UTCEPSS rescore
  18. 2026-06-19 19:26 UTCEPSS rescore
  19. 2026-06-18 17:52 UTCEPSS rescore
  20. 2026-06-18 17:52 UTCEPSS rescore
  21. 2026-06-17 17:53 UTCEPSS rescore
  22. 2026-06-17 04:15 UTCEG score recompute
  23. 2026-06-17 04:15 UTCGHSA enrichment
  24. 2026-06-16 17:53 UTCEPSS rescore
  25. 2026-06-16 02:26 UTCEG score recompute
  26. 2026-06-16 02:26 UTCGHSA enrichment
  27. 2026-06-15 17:49 UTCEPSS rescore
  28. 2026-06-15 17:49 UTCEPSS rescore
  29. 2026-06-15 00:41 UTCEG score recompute
  30. 2026-06-15 00:41 UTCGHSA enrichment
  31. 2026-06-14 23:18 UTCEPSS rescore
  32. 2026-06-13 23:00 UTCEPSS rescore
  33. 2026-06-13 22:59 UTCEG score recompute
  34. 2026-06-13 22:59 UTCGHSA enrichment
  35. 2026-06-12 23:12 UTCEPSS rescore
  36. 2026-06-12 23:12 UTCEPSS rescore
  37. 2026-06-12 21:16 UTCEG score recompute
  38. 2026-06-12 21:16 UTCGHSA enrichment
  39. 2026-06-11 19:34 UTCEG score recompute
  40. 2026-06-11 19:34 UTCGHSA enrichment
  41. 2026-06-11 14:00 UTCEPSS rescore
  42. 2026-06-10 22:19 UTCEPSS rescore
  43. 2026-06-10 17:53 UTCEG score recompute
  44. 2026-06-10 17:53 UTCGHSA enrichment
  45. 2026-06-10 13:22 UTCEPSS rescore
  46. 2026-06-09 16:12 UTCEG score recompute
  47. 2026-06-09 16:11 UTCGHSA enrichment
  48. 2026-06-08 14:30 UTCEG score recompute
  49. 2026-06-08 14:30 UTCGHSA enrichment
  50. 2026-06-08 14:17 UTCEPSS rescore
  51. 2026-06-07 15:25 UTCEPSS rescore
  52. 2026-06-07 12:48 UTCEG score recompute
  53. 2026-06-07 12:48 UTCGHSA enrichment
  54. 2026-06-06 13:47 UTCEPSS rescore
  55. 2026-06-06 11:07 UTCEG score recompute
  56. 2026-06-06 11:07 UTCGHSA enrichment
  57. 2026-06-05 22:47 UTCEPSS rescore
  58. 2026-06-05 09:25 UTCEG score recompute
  59. 2026-06-05 09:25 UTCGHSA enrichment
  60. 2026-06-05 06:10 UTCEPSS rescore
  61. 2026-06-04 13:12 UTCEPSS rescore
  62. 2026-06-04 07:43 UTCEG score recompute
  63. 2026-06-04 07:43 UTCGHSA enrichment
  64. 2026-06-03 06:01 UTCEG score recompute
  65. 2026-06-03 06:01 UTCGHSA enrichment
  66. 2026-06-02 20:13 UTCEPSS rescore
  67. 2026-06-02 04:19 UTCEG score recompute
  68. 2026-06-02 04:19 UTCGHSA enrichment
  69. 2026-06-01 13:52 UTCEPSS rescore
  70. 2026-06-01 02:37 UTCEG score recompute▼ 1.60
  71. 2026-06-01 02:37 UTCGHSA enrichment
  72. 2026-05-31 22:30 UTCEPSS rescore
  73. 2026-05-31 22:30 UTCEPSS rescore
  74. 2026-05-31 00:16 UTCEPSS rescore
  75. 2026-05-31 00:16 UTCEPSS rescore

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-6826?
CVE-2026-6826 is a medium vulnerability published on May 21, 2026. Concrete CMS 9.5.0 and below is vulnerable to unauthenticated file usage disclosure via missing permission check in the usage controller. Any unauthenticated visitor can request /ccm/system/dialogs/file/usage/{fID} with any file ID and receive a list of every page that references that file,…
When was CVE-2026-6826 disclosed?
CVE-2026-6826 was first published in the National Vulnerability Database on May 21, 2026, with the most recent update on May 26, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-6826 actively exploited?
CVE-2026-6826 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 16.3% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2026-6826?
CVE-2026-6826 has a CVSS v3 base score of 5.3 (NVD).
How do I remediate CVE-2026-6826?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-6826, 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-2026-6826

Explore →

Is Your Infrastructure Affected by CVE-2026-6826?

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

Start Free Scan →Browse All CVEs