CVE-2026-8134

HIGHNVD 7.27.2—
EchelonGraph scoreMEDIUM confidence

Score 7.2 from GitHub Security Advisory (severity: CRITICAL) published 2026-05-21. NVD baseline CVSS 7.2; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, nvd
7.2
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS: 1%CVSS: 7.2Exploit: 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 fails to sanitize path traversal sequences in the ptComposerFormLayoutSetControlCustomTemplate field when saving page type composer form layouts. An authenticated rogue administrator with composer form editing rights can exploit this to include arbitrary readable files on the server. Combined with the file uploader's extension-only validation (which permits PHP code in files saved with image extensions like .png), this can result in authenticated remote code execution. The Concrete CMS security team gave this vulnerability a CVSS v.4.0 score of 9.4 with vector CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H   Thanks Yonatan Drori (Tenzai) for reporting.

CVSS v3
7.2
EG Score
7.2(medium)
EPSS
50.2%
KEV
Not listed

Published

May 21, 2026

Last Modified

May 26, 2026

Advisory Details (1)

Auto-updated May 21, 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-2026-8134(1)

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

Weakness Classification(3)

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

Data Freshness Timeline

(refreshed 11× in last 7d / 66× 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 133 total refreshes for this CVE.

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

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-8134?
CVE-2026-8134 is a high vulnerability published on May 21, 2026. Concrete CMS 9.5.0 and below fails to sanitize path traversal sequences in the ptComposerFormLayoutSetControlCustomTemplate field when saving page type composer form layouts. An authenticated rogue administrator with composer form editing rights can exploit this to include arbitrary readable files…
When was CVE-2026-8134 disclosed?
CVE-2026-8134 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-2026-8134 actively exploited?
CVE-2026-8134 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 50.2% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2026-8134?
CVE-2026-8134 has a CVSS v3 base score of 7.2 (NVD).
How do I remediate CVE-2026-8134?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-8134, 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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