CVE-2026-7886

MEDIUMNVD 4.34.3—
EchelonGraph scoreMEDIUM confidence

This medium-severity CVE scores 4.3 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
4.3
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS: 0%CVSS: 4.3Exploit: 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 IDOR in AddMessage/UpdateMessage via attachments[] parameter which can lead to file permission bypass. The AddMessage and UpdateMessage conversation controllers accept user-supplied file attachment IDs and load files directly via $em->find(File::class, $attachmentID) without checking per-file permissions (canViewFile()). A user who can post in any conversation can reference any file in the CMS file manager by its sequential ID, effectively bypassing the file permission system.  The Concrete CMS security team gave this vulnerability a CVSS v.4.0 score of 2.3 with a vector CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N. Thanks Tristan Mandani for reporting. if a site truly has private files, the owner should set up a private storage location https://documentation.concretecms.org/user-guide/editors-reference/dashboard/system-and-maintenance/files/file-storage-locations outside of the webroot so that permissions can be checked on view as well. That way, even if a authorized user attaches a file, or otherwise links to it, unauthorized users won't be able to view the file.

CVSS v3
4.3
EG Score
4.3(medium)
EPSS
20.6%
KEV
Not listed

Published

May 21, 2026

Last Modified

May 22, 2026

Advisory Details (1)

Auto-updated Jun 27, 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-2026-7886(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)
Packagist(1)
PackageVulnerable rangeFixed inDependents
concrete5/concrete58.0 ... 9.5.0RC2 (89 versions)9.5.1—

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 11× in last 7d / 49× 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 101 total refreshes for this CVE.

  1. 2026-07-13 06:13 UTCEPSS rescore
  2. 2026-07-12 05:46 UTCEPSS rescore
  3. 2026-07-11 08:27 UTCEPSS rescore
  4. 2026-07-09 19:10 UTCEPSS rescore
  5. 2026-07-09 19:10 UTCEPSS rescore
  6. 2026-07-08 15:16 UTCEPSS rescore
  7. 2026-07-08 15:16 UTCEPSS rescore
  8. 2026-07-07 13:46 UTCEPSS rescore
  9. 2026-07-07 13:46 UTCEPSS rescore
  10. 2026-07-06 16:27 UTCEPSS rescore
  11. 2026-07-06 16:27 UTCEPSS rescore
  12. 2026-07-06 02:23 UTCEPSS rescore
  13. 2026-07-06 02:23 UTCEPSS rescore
  14. 2026-07-05 02:31 UTCEPSS rescore
  15. 2026-07-05 02:30 UTCEPSS rescore
  16. 2026-07-01 15:07 UTCEPSS rescore
  17. 2026-06-30 23:22 UTCEPSS rescore
  18. 2026-06-29 19:54 UTCEG score recompute
  19. 2026-06-29 14:06 UTCEPSS rescore
  20. 2026-06-28 14:07 UTCEPSS rescore
  21. 2026-06-28 04:56 UTCEPSS rescore
  22. 2026-06-27 19:33 UTCEG score recompute
  23. 2026-06-27 03:08 UTCEPSS rescore
  24. 2026-06-26 19:17 UTCEG score recompute
  25. 2026-06-25 14:12 UTCEG score recompute
Show 75 more
  1. 2026-06-25 13:50 UTCEPSS rescore
  2. 2026-06-24 14:05 UTCEPSS rescore
  3. 2026-06-23 21:33 UTCEPSS rescore
  4. 2026-06-22 14:25 UTCEPSS rescore
  5. 2026-06-21 14:56 UTCEPSS rescore
  6. 2026-06-21 01:59 UTCEPSS rescore
  7. 2026-06-19 19:26 UTCEPSS rescore
  8. 2026-06-18 17:52 UTCEPSS rescore
  9. 2026-06-17 19:56 UTCEG score recompute
  10. 2026-06-17 19:56 UTCGHSA enrichment
  11. 2026-06-17 17:53 UTCEPSS rescore
  12. 2026-06-16 21:03 UTCEG score recompute
  13. 2026-06-16 21:03 UTCGHSA enrichment
  14. 2026-06-16 17:53 UTCEPSS rescore
  15. 2026-06-15 22:47 UTCEG score recompute
  16. 2026-06-15 22:46 UTCGHSA enrichment
  17. 2026-06-15 17:49 UTCEPSS rescore
  18. 2026-06-15 17:49 UTCEPSS rescore
  19. 2026-06-14 23:57 UTCEG score recompute
  20. 2026-06-14 23:57 UTCGHSA enrichment
  21. 2026-06-14 23:18 UTCEPSS rescore
  22. 2026-06-14 01:45 UTCEG score recompute
  23. 2026-06-14 01:45 UTCGHSA enrichment
  24. 2026-06-13 23:00 UTCEPSS rescore
  25. 2026-06-13 03:24 UTCEG score recompute
  26. 2026-06-13 03:24 UTCGHSA enrichment
  27. 2026-06-12 23:12 UTCEPSS rescore
  28. 2026-06-12 23:12 UTCEPSS rescore
  29. 2026-06-12 05:07 UTCEG score recompute
  30. 2026-06-12 05:07 UTCGHSA enrichment
  31. 2026-06-11 14:00 UTCEPSS rescore
  32. 2026-06-11 06:55 UTCEG score recompute
  33. 2026-06-11 06:55 UTCGHSA enrichment
  34. 2026-06-10 22:19 UTCEPSS rescore
  35. 2026-06-10 13:22 UTCEPSS rescore
  36. 2026-06-10 08:44 UTCEG score recompute
  37. 2026-06-10 08:44 UTCGHSA enrichment
  38. 2026-06-09 10:32 UTCEG score recompute
  39. 2026-06-09 10:32 UTCGHSA enrichment
  40. 2026-06-08 14:17 UTCEPSS rescore
  41. 2026-06-08 12:20 UTCEG score recompute
  42. 2026-06-08 12:20 UTCGHSA enrichment
  43. 2026-06-07 15:25 UTCEPSS rescore
  44. 2026-06-07 14:08 UTCEG score recompute
  45. 2026-06-07 14:08 UTCGHSA enrichment
  46. 2026-06-06 15:48 UTCEG score recompute
  47. 2026-06-06 15:48 UTCGHSA enrichment
  48. 2026-06-06 13:47 UTCEPSS rescore
  49. 2026-06-05 22:47 UTCEPSS rescore
  50. 2026-06-05 17:36 UTCEG score recompute
  51. 2026-06-05 17:36 UTCGHSA enrichment
  52. 2026-06-05 06:10 UTCEPSS rescore
  53. 2026-06-04 19:23 UTCEG score recompute
  54. 2026-06-04 19:23 UTCGHSA enrichment
  55. 2026-06-04 13:12 UTCEPSS rescore
  56. 2026-06-03 21:11 UTCEG score recompute
  57. 2026-06-03 21:11 UTCGHSA enrichment
  58. 2026-06-02 22:59 UTCEG score recompute
  59. 2026-06-02 22:59 UTCGHSA enrichment
  60. 2026-06-02 20:13 UTCEPSS rescore
  61. 2026-06-02 00:47 UTCEG score recompute
  62. 2026-06-02 00:47 UTCGHSA enrichment
  63. 2026-06-01 13:52 UTCEPSS rescore
  64. 2026-06-01 02:35 UTCEG score recompute▲ 2.00
  65. 2026-06-01 02:35 UTCGHSA enrichment
  66. 2026-05-31 22:30 UTCEPSS rescore
  67. 2026-05-31 00:16 UTCEPSS rescore
  68. 2026-05-29 13:44 UTCEPSS rescore
  69. 2026-05-28 13:44 UTCEPSS rescore
  70. 2026-05-27 13:40 UTCEPSS rescore
  71. 2026-05-27 13:40 UTCEPSS rescore
  72. 2026-05-26 13:44 UTCEPSS rescore
  73. 2026-05-26 07:18 UTCEPSS rescore
  74. 2026-05-23 00:07 UTCEG score recompute
  75. 2026-05-22 22:08 UTCEG score recompute

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-7886?
CVE-2026-7886 is a medium vulnerability published on May 21, 2026. Concrete CMS 9.5.0 and below is vulnerable to IDOR in AddMessage/UpdateMessage via attachments[] parameter which can lead to file permission bypass. The AddMessage and UpdateMessage conversation controllers accept user-supplied file attachment IDs and load files directly via $em->find(File::class,…
When was CVE-2026-7886 disclosed?
CVE-2026-7886 was first published in the National Vulnerability Database on May 21, 2026, with the most recent update on May 22, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-7886 actively exploited?
CVE-2026-7886 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 20.6% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2026-7886?
CVE-2026-7886 has a CVSS v3 base score of 4.3 (NVD).
How do I remediate CVE-2026-7886?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-7886, 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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