CVE-2026-7886

MEDIUMNVD 4.34.3
EchelonGraph scoreMEDIUM confidence

“—” beside the score: it is equal to NVD's CVSS score.

This medium-severity CVE scores 4.3 under NVD CVSS v3. EPSS exploit probability: 0.5% (38th percentile of EPSS-scored CVEs). No GitHub Security Advisory CVSS is on record for this CVE.

Triggered by: Headline CVSS from NVD CVSS v3
Sources: EPSS, NVD CVSS v3
4.3EG
EchelonGraph verdictMonitorRemediate within your standard update timelines (the SSVC decision on this page).
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0.5%CVSS: 4.3Exploit: None knownExposed services: Not assessed

A fix is available — apply it.

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
4.3MEDIUMmedium confidence
EG Risk
20
EG Risk 20/100

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 (value × EchelonGraph’s weight)
Severity43% × 45%
The EG Score, 4.3 of 10.
Exploitation0.5% × 40%
FIRST EPSS: the 30-day exploitation probability when EchelonGraph scored this CVE.
Automatability0% × 15%
CISA's SSVC Automatable value: no (Vulnrichment).
SSVC (CISA's decision table, applied by EchelonGraph): Track at every mission impact level.
Exploitation none (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE.
Action: A fix is available. Apply it within your standard update timelines.
EPSS PROB
0.5%
EPSS %ILE
38th
KEV
Not listed

SSVC (CISA's decision table, applied by EchelonGraph)Track at every mission impact level.

A fix is available. Apply it within your standard update timelines.

Exploitation none (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE. Mission impact is CISA's Mission & Well-being decision point, and only you can judge it. CISA's table makes it high when Mission Prevalence is Essential — the vulnerable component "directly provides capabilities that constitute at least one MEF for at least one entity" (MEF: mission essential function) — or when Public Well-Being Impact is Irreversible: "multiple fatalities are likely", the cyber-physical system "is likely lost or destroyed", "extreme or serious externalities" are imposed on other parties, or social systems such as elections or the financial grid "are destabilized and potentially collapse". CISA's decision table

BOD 26-04 (CISA's remediation timeline, Table 1)60 days if the affected system is publicly exposed; Fix on system upgrade if it is not.

In CISA KEV no (CISA's KEV catalog) · Automatable no (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). Whether your system is publicly exposed is yours to answer. BOD 26-04 binds US Federal Civilian Executive Branch agencies; for anyone else it is CISA's published timeline, a reference rather than an obligation. The directive · how EchelonGraph applies it

Published

May 21, 2026

Last Modified

July 23, 2026

Advisory Details (1)

Auto-updated Jun 27, 2026
Patch available.
Web page

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 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(1)

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

Data Freshness Timeline

(refreshed 10× in last 7d / 30× in last 30d)

Each row is a time one of our pipelines fetched, updated or re-scored this CVE. 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. An arrow marks a change the record states ("CVSS v3 → 9.1"); EPSS and GHSA rows show the values recorded at that time, not what changed (EPSS values are rounded; hover one for the exact figures). Most recent first.

Showing the most recent 93 of 182 refreshes on record for this CVE.

A repeat, a row identical to one the same pipeline wrote less than 10 seconds earlier, is not a separate refresh and is not counted. 7 repeat rows among the latest 100 are merged into the row they repeat. The 89 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

  1. 2026-10-11 19:22 UTCEG score recompute
  2. 2026-10-11 16:38 UTCEG score recompute
  3. 2026-10-11 13:57 UTCEG score recompute
  4. 2026-10-11 13:49 UTCEPSS rescoreEPSS 0.5% · 38th percentile
  5. 2026-10-10 20:00 UTCEPSS rescoreEPSS 0.5% · 38th percentile
  6. 2026-10-09 20:07 UTCEPSS rescoreEPSS 0.5% · 38th percentile
  7. 2026-10-08 17:13 UTCEPSS rescoreEPSS 0.5% · 38th percentile
  8. 2026-10-07 23:48 UTCEPSS rescoreEPSS 0.5% · 38th percentile
  9. 2026-10-06 15:18 UTCEPSS rescoreEPSS 0.5% · 38th percentile
  10. 2026-10-05 17:43 UTCEPSS rescoreEPSS 0.5% · 38th percentile
  11. 2026-10-04 23:22 UTCEPSS rescoreEPSS 0.5% · 38th percentile
  12. 2026-10-03 14:26 UTCEPSS rescoreEPSS 0.5% · 38th percentile
  13. 2026-10-02 17:57 UTCEPSS rescoreEPSS 0.5% · 38th percentile
  14. 2026-10-01 19:50 UTCEPSS rescoreEPSS 0.5% · 38th percentile
  15. 2026-09-30 15:04 UTCEPSS rescoreEPSS 0.5% · 38th percentile
  16. 2026-09-30 02:40 UTCOSV refresh
  17. 2026-09-29 15:24 UTCEPSS rescoreEPSS 0.5% · 38th percentile
  18. 2026-09-28 13:52 UTCEPSS rescoreEPSS 0.5% · 38th percentile
  19. 2026-09-27 13:48 UTCEPSS rescoreEPSS 0.5% · 38th percentile
  20. 2026-09-26 15:59 UTCEPSS rescoreEPSS 0.5% · 38th percentile
  21. 2026-09-26 00:28 UTCEPSS rescoreEPSS 0.5% · 38th percentile
  22. 2026-09-24 14:04 UTCEPSS rescoreEPSS 0.5% · 38th percentile
  23. 2026-09-23 17:54 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  24. 2026-09-22 16:01 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  25. 2026-09-21 21:09 UTCEPSS rescoreEPSS 0.3% · 21st percentile
Show 68 more
  1. 2026-09-20 20:16 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  2. 2026-09-18 19:28 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  3. 2026-09-16 14:08 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  4. 2026-09-16 05:15 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  5. 2026-09-15 03:12 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  6. 2026-09-11 14:53 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  7. 2026-09-11 04:23 UTCOSV refresh
  8. 2026-09-08 22:01 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  9. 2026-09-06 13:48 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  10. 2026-09-04 05:07 UTCEPSS rescoreEPSS 0.3% · 20th percentile
  11. 2026-09-02 14:12 UTCEPSS rescoreEPSS 0.3% · 20th percentile
  12. 2026-09-01 13:54 UTCEPSS rescoreEPSS 0.3% · 20th percentile
  13. 2026-09-01 04:40 UTCEPSS rescoreEPSS 0.3% · 20th percentile
  14. 2026-08-30 19:17 UTCEPSS rescoreEPSS 0.3% · 20th percentile
  15. 2026-08-30 01:22 UTCEPSS rescoreEPSS 0.3% · 20th percentile
  16. 2026-08-28 21:42 UTCEPSS rescoreEPSS 0.3% · 20th percentile
  17. 2026-08-27 14:25 UTCEPSS rescoreEPSS 0.3% · 20th percentile
  18. 2026-08-26 14:47 UTCEPSS rescoreEPSS 0.3% · 20th percentile
  19. 2026-08-25 13:49 UTCEPSS rescoreEPSS 0.3% · 20th percentile
  20. 2026-08-24 14:18 UTCEPSS rescoreEPSS 0.3% · 20th percentile
  21. 2026-08-23 16:45 UTCEG score recompute
  22. 2026-08-23 00:19 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  23. 2026-08-21 23:49 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  24. 2026-08-21 21:43 UTCEG score recompute
  25. 2026-08-20 22:56 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  26. 2026-08-20 18:41 UTCEG score recompute
  27. 2026-08-19 17:04 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  28. 2026-08-18 13:49 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  29. 2026-08-17 13:47 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  30. 2026-08-17 09:46 UTCEG score recompute
  31. 2026-08-16 14:56 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  32. 2026-08-16 03:21 UTCEG score recompute
  33. 2026-08-16 02:15 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  34. 2026-08-15 01:31 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  35. 2026-08-14 01:54 UTCEG score recompute
  36. 2026-08-13 22:00 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  37. 2026-08-12 21:17 UTCEG score recompute
  38. 2026-08-12 13:51 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  39. 2026-08-11 22:54 UTCEG score recompute
  40. 2026-08-11 13:43 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  41. 2026-08-11 00:30 UTCEG score recompute
  42. 2026-08-11 00:00 UTCEPSS rescoreEPSS 0.3% · 20th percentile
  43. 2026-08-09 23:37 UTCEG score recompute
  44. 2026-08-09 13:47 UTCEPSS rescoreEPSS 0.3% · 20th percentile
  45. 2026-08-07 17:36 UTCEG score recompute
  46. 2026-08-06 19:24 UTCEG score recompute
  47. 2026-08-06 13:47 UTCEPSS rescoreEPSS 0.3% · 20th percentile
  48. 2026-08-05 21:12 UTCEG score recompute
  49. 2026-08-05 19:17 UTCEPSS rescoreEPSS 0.3% · 20th percentile
  50. 2026-08-04 15:10 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  51. 2026-08-04 10:39 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  52. 2026-08-03 16:48 UTCEG score recompute
  53. 2026-08-03 10:36 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  54. 2026-08-02 15:33 UTCEG score recompute
  55. 2026-08-02 02:27 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  56. 2026-08-01 17:21 UTCEG score recompute
  57. 2026-08-01 04:16 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  58. 2026-07-30 16:28 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  59. 2026-07-30 01:30 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  60. 2026-07-29 17:38 UTCEG score recompute
  61. 2026-07-28 15:37 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  62. 2026-07-27 14:14 UTCEPSS rescoreEPSS 0.3% · 20th percentile
  63. 2026-07-26 14:54 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  64. 2026-07-26 08:08 UTCEG score recompute
  65. 2026-07-25 14:18 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  66. 2026-07-24 14:18 UTCEPSS rescoreEPSS 0.3% · 20th percentile
  67. 2026-07-23 14:18 UTCEPSS rescoreEPSS 0.3% · 20th percentile
  68. 2026-07-23 03:23 UTCEG score recompute

Related CVEs(same product + same CWE)

Frequently asked(5)

What is CVE-2026-7886?
CVE-2026-7886 is a medium-severity vulnerability; its CVE record was 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 the CVE record for CVE-2026-7886 published?
The CVE record for CVE-2026-7886 was published on May 21, 2026. That is the record's publication date; the vulnerability itself may have been made public earlier. EchelonGraph's copy of the record carries a last-modified date of July 23, 2026; the record at its source may have been updated since.
Is CVE-2026-7886 actively exploited?
CVE-2026-7886 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.5% probability of exploitation in the next 30 days (38th percentile of EPSS-scored CVEs).
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?
A fix for CVE-2026-7886 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-7886 are linked in the Vendor Advisories panel on this page.

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