CVE-2026-8140

MEDIUMNVD 6.56.5—
EchelonGraph scoreMEDIUM confidence

Score 6.5 from GitHub Security Advisory (severity: HIGH) published 2026-05-21. NVD baseline CVSS 6.5; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, nvd
Trending — 3 sources updated this week
6.5
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS: 0%CVSS: 6.5Exploit: 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 does not validate a CSRF token before processing requests to /dashboard/extend/install/download/. The download() method in concrete/controllers/single_page/dashboard/extend/install.php checks only the canInstallPackages() permission before fetching a remote marketplace package and writing it to the server's DIR_PACKAGES directory. Because the endpoint is a state-changing GET route with no token enforcement, an attacker who can cause an authenticated administrator to visit a crafted page can force an arbitrary marketplace package to be downloaded. In order to be vulnerable, the victim must be passing canInstallPackages() and the site must be connected to the Concrete marketplace. The Concrete CMS security team gave this vulnerability a CVSS v.4.0 score of 7.5 with vector CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N. Thanks  https://github.com/maru1009  for reporting.

CVSS v3
6.5
EG Score
6.5(medium)
EG Risk
29(Track)
EG Risk 29/100SSVC: 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
Severity65% × 45%
Exploitation0% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS
2.0%
KEV
Not listed

Published

May 21, 2026

Last Modified

May 26, 2026

Advisory Details (1)

Auto-updated Jun 12, 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-2026-8140(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 / 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.

  1. 2026-07-23 03:23 UTCEG score recompute
  2. 2026-07-22 14:08 UTCEPSS rescore
  3. 2026-07-21 15:25 UTCEPSS rescore
  4. 2026-07-21 15:25 UTCEPSS rescore
  5. 2026-07-20 17:08 UTCEPSS rescore
  6. 2026-07-19 14:31 UTCEPSS rescore
  7. 2026-07-19 02:29 UTCEPSS rescore
  8. 2026-07-18 10:04 UTCEPSS rescore
  9. 2026-07-17 21:59 UTCOSV refresh
  10. 2026-07-16 17:03 UTCEPSS rescore
  11. 2026-07-15 16:57 UTCEPSS rescore
  12. 2026-07-13 22:31 UTCEPSS rescore
  13. 2026-07-13 06:13 UTCEPSS rescore
  14. 2026-07-11 08:27 UTCEPSS rescore
  15. 2026-07-09 19:10 UTCEPSS rescore
  16. 2026-07-08 15:16 UTCEPSS rescore
  17. 2026-07-08 15:16 UTCEPSS rescore
  18. 2026-07-07 13:46 UTCEPSS rescore
  19. 2026-07-07 13:46 UTCEPSS rescore
  20. 2026-07-06 16:27 UTCEPSS rescore
  21. 2026-07-06 16:27 UTCEPSS rescore
  22. 2026-07-06 02:23 UTCEPSS rescore
  23. 2026-07-06 02:23 UTCEPSS rescore
  24. 2026-07-04 06:31 UTCEPSS rescore
  25. 2026-07-04 06:31 UTCEPSS rescore
Show 59 more
  1. 2026-07-01 15:07 UTCEPSS rescore
  2. 2026-06-30 23:22 UTCEPSS rescore
  3. 2026-06-29 14:06 UTCEPSS rescore
  4. 2026-06-28 14:07 UTCEPSS rescore
  5. 2026-06-27 03:08 UTCEPSS rescore
  6. 2026-06-25 13:50 UTCEPSS rescore
  7. 2026-06-24 14:05 UTCEPSS rescore
  8. 2026-06-23 21:33 UTCEPSS rescore
  9. 2026-06-22 14:25 UTCEPSS rescore
  10. 2026-06-21 14:56 UTCEPSS rescore
  11. 2026-06-21 01:59 UTCEPSS rescore
  12. 2026-06-19 19:26 UTCEPSS rescore
  13. 2026-06-18 17:52 UTCEPSS rescore
  14. 2026-06-17 20:26 UTCGHSA enrichment
  15. 2026-06-17 17:53 UTCEPSS rescore
  16. 2026-06-16 19:42 UTCGHSA enrichment
  17. 2026-06-15 17:49 UTCEPSS rescore
  18. 2026-06-15 17:49 UTCEPSS rescore
  19. 2026-06-15 15:37 UTCGHSA enrichment
  20. 2026-06-14 23:18 UTCEPSS rescore
  21. 2026-06-14 12:50 UTCGHSA enrichment
  22. 2026-06-13 23:00 UTCEPSS rescore
  23. 2026-06-13 12:05 UTCGHSA enrichment
  24. 2026-06-12 23:12 UTCEPSS rescore
  25. 2026-06-12 23:12 UTCEPSS rescore
  26. 2026-06-12 10:44 UTCGHSA enrichment
  27. 2026-06-11 14:00 UTCEPSS rescore
  28. 2026-06-11 10:00 UTCGHSA enrichment
  29. 2026-06-10 22:19 UTCEPSS rescore
  30. 2026-06-10 13:22 UTCEPSS rescore
  31. 2026-06-10 09:16 UTCGHSA enrichment
  32. 2026-06-09 08:32 UTCGHSA enrichment
  33. 2026-06-08 14:17 UTCEPSS rescore
  34. 2026-06-08 07:47 UTCGHSA enrichment
  35. 2026-06-07 15:25 UTCEPSS rescore
  36. 2026-06-07 07:03 UTCGHSA enrichment
  37. 2026-06-06 13:47 UTCEPSS rescore
  38. 2026-06-06 06:18 UTCGHSA enrichment
  39. 2026-06-05 22:47 UTCEPSS rescore
  40. 2026-06-05 06:10 UTCEPSS rescore
  41. 2026-06-05 05:34 UTCGHSA enrichment
  42. 2026-06-04 13:12 UTCEPSS rescore
  43. 2026-06-04 04:50 UTCGHSA enrichment
  44. 2026-06-03 04:06 UTCGHSA enrichment
  45. 2026-06-02 20:13 UTCEPSS rescore
  46. 2026-06-02 03:21 UTCGHSA enrichment
  47. 2026-06-01 13:52 UTCEPSS rescore
  48. 2026-06-01 02:37 UTCEG score recompute▼ 1.00
  49. 2026-06-01 02:37 UTCGHSA enrichment
  50. 2026-05-31 22:30 UTCEPSS rescore
  51. 2026-05-31 00:16 UTCEPSS rescore
  52. 2026-05-29 13:44 UTCEPSS rescore
  53. 2026-05-28 13:44 UTCEPSS rescore
  54. 2026-05-27 13:40 UTCEPSS rescore
  55. 2026-05-27 13:40 UTCEPSS rescore
  56. 2026-05-26 13:44 UTCEPSS rescore
  57. 2026-05-26 07:18 UTCEPSS rescore
  58. 2026-05-21 22:45 UTCEG score recompute
  59. 2026-05-21 22:45 UTCGHSA enrichment

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-8140?
CVE-2026-8140 is a medium vulnerability published on May 21, 2026. Concrete CMS 9.5.0 and below does not validate a CSRF token before processing requests to /dashboard/extend/install/download/<remoteId>. The download() method in concrete/controllers/singlepage/dashboard/extend/install.php checks only the canInstallPackages() permission before fetching a remote…
When was CVE-2026-8140 disclosed?
CVE-2026-8140 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-2026-8140 actively exploited?
CVE-2026-8140 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 2.0% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2026-8140?
CVE-2026-8140 has a CVSS v3 base score of 6.5 (NVD).
How do I remediate CVE-2026-8140?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-8140, 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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