CVE-2026-8337

MEDIUMNVD 5.35.3—
EchelonGraph scoreMEDIUM confidence

Score 5.3 from GitHub Security Advisory published 2026-05-22. NVD baseline CVSS 5.3; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, nvd
5.3EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0.3%CVSS: 5.3Exploit: None knownExposed services: Not assessed

A fix is available — apply it.

Concrete CMS 9.5.0 and below is vulnerable to IDOR in surveys. To be vulnerable, a site would have to be configured in such a way that both public and private surveys are present on the site. An unauthenticated attacker can vote in the restricted survey by submitting the restricted optionID through the public survey’s endpoint. The Concrete CMS security team gave this vulnerability a CVSS v.4.0 score of 6.3 with vector CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N. Thanks  Zer0daySec https://github.com/Zee99y  for reporting

CVSS v3
5.3
EG Score
5.3MEDIUMmedium confidence
EG Risk
39
EG Risk 39/100

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
Severity53% × 45%
Exploitation0% × 40%
Automatability100% × 15%
EPSS PROB
0.3%
EPSS %ILE
23rd
KEV
Not listed

Published

May 21, 2026

Last Modified

July 23, 2026

Advisory Details (1)

Auto-updated Jun 16, 2026
Patch available.
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-2026-8337(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 rangeFix by version rangeDependents
concrete5/concrete58.0 ... 9.5.0RC2 (89 versions)
  • every version up to 9.5.1: fixed in 9.5.1
—

Weakness Classification(2)

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

Data Freshness Timeline

(refreshed 6× in last 7d / 27× 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 184 total refreshes for this CVE.

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

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Frequently asked(5)

What is CVE-2026-8337?
CVE-2026-8337 is a medium vulnerability published on May 21, 2026. Concrete CMS 9.5.0 and below is vulnerable to IDOR in surveys. To be vulnerable, a site would have to be configured in such a way that both public and private surveys are present on the site. An unauthenticated attacker can vote in the restricted survey by submitting the restricted optionID through…
When was CVE-2026-8337 disclosed?
CVE-2026-8337 was first published on May 21, 2026, with the most recent update on July 23, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-8337 actively exploited?
CVE-2026-8337 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.3% probability of exploitation in the next 30 days (23rd percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-8337?
CVE-2026-8337 has a CVSS v3 base score of 5.3 (NVD).
How do I remediate CVE-2026-8337?
A fix for CVE-2026-8337 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-8337 are linked in the Vendor Advisories panel on this page.

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