CVE-2026-8353

MEDIUMNVD 4.84.8—
EchelonGraph scoreMEDIUM confidence

Score 4.8 from GitHub Security Advisory (severity: LOW) published 2026-05-26. NVD baseline CVSS 4.8; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, nvd
4.8EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 4.8Exploit: None knownExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

Concrete CMS version 9.0 to 9.5.0 is vulnerable to Stored XSS via page name in the Atomik theme. A rogue editor can inject arbitrary JavaScript that executes in the context of any authenticated user visiting the affected account pages. This can lead to session hijacking, credential theft, malicious actions performed on behalf of users, and potential privilege escalation. The Concrete CMS security team gave this vulnerability a CVSS v.4.0 score of 2.1 with vector CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N. Thanks Yonatan Drori (Tenzai) for reporting.

CVSS v3
4.8
EG Score
4.8(medium)
EG Risk
22(Track)
EG Risk 22/100SSVC: 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
Severity48% × 45%
Exploitation0% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
5%
KEV
Not listed

Published

May 26, 2026

Last Modified

July 23, 2026

Advisory Details (1)

Auto-updated Jul 26, 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-2026-8353(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/concrete59.0.0 ... 9.5.0RC2 (45 versions)9.5.1—

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 8× in last 7d / 38× 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 103 total refreshes for this CVE.

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

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-8353?
CVE-2026-8353 is a medium vulnerability published on May 26, 2026. Concrete CMS version 9.0 to 9.5.0 is vulnerable to Stored XSS via page name in the Atomik theme. A rogue editor can inject arbitrary JavaScript that executes in the context of any authenticated user visiting the affected account pages. This can lead to session hijacking, credential theft, malicious…
When was CVE-2026-8353 disclosed?
CVE-2026-8353 was first published in the National Vulnerability Database on May 26, 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-2026-8353 actively exploited?
CVE-2026-8353 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0% probability of exploitation in the next 30 days, which ranks it in the top 95.3% of all scored CVEs.
What is the CVSS score of CVE-2026-8353?
CVE-2026-8353 has a CVSS v3 base score of 4.8 (NVD).
How do I remediate CVE-2026-8353?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-8353, 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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