CVE-2026-18111

HIGHPre-NVD 8.58.5—
EchelonGraph scoreMEDIUM confidence

This high-severity CVE scores 8.5 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.3%, top 77% of all CVEs by exploit prediction. GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).

Triggered by: NVD CVSS baseline
Sources: epss, secondary
Trending — 4 sources updated this week
8.5EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 8.5Exploit: None knownExposed: 0

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

Concrete CMS 9 before 9.5.3 was vulnerable to stored cross-site scripting (XSS) in the Feature, Feature Link, Hero Image, and Image blocks and before Concrete 8.5.21 in the feature and Image blocks because the external link URL was insufficiently validated by the link filter and was rendered without output escaping. A user with page-editing permissions (such as Add Block combined with Edit Contents on a single page) could store a crafted external link value that broke out of the link markup and injected arbitrary JavaScript. The script executed in the browser session of any user who subsequently viewed, previewed, or edited the affected page, which could lead to session hijacking and escalation of privileges up to full administrative takeover. The Concrete CMS security team gave this vulnerability a CVSS v4.0 score of 8.5 with vector CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N. Thanks to KhanMarshai for reporting this issue.

CVSS v3
8.5
EG Score
8.5(medium)
EG Risk
43(Track)
EG Risk 43/100SSVC: 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
Severity85% × 45%
Exploitation0% × 40%
Automatability30% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
23%
KEV
Not listed

Published

September 15, 2026

Last Modified

September 16, 2026

References (1)

Vendor Advisories for CVE-2026-18111(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 20× in last 7d / 20× 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. 2026-09-20 18:49 UTCGHSA enrichment
  2. 2026-09-20 06:58 UTCGHSA enrichment
  3. 2026-09-19 18:43 UTCEG score recompute
  4. 2026-09-19 18:43 UTCGHSA enrichment
  5. 2026-09-19 06:52 UTCEG score recompute
  6. 2026-09-19 06:52 UTCGHSA enrichment
  7. 2026-09-18 19:27 UTCEPSS rescore
  8. 2026-09-18 19:02 UTCGHSA enrichment
  9. 2026-09-18 07:12 UTCEG score recompute
  10. 2026-09-18 07:12 UTCGHSA enrichment
  11. 2026-09-17 19:21 UTCGHSA enrichment
  12. 2026-09-17 07:16 UTCGHSA enrichment
  13. 2026-09-16 19:23 UTCGHSA enrichment
  14. 2026-09-16 17:55 UTCEG score recompute
  15. 2026-09-16 17:55 UTCGHSA enrichment
  16. 2026-09-16 14:07 UTCEPSS rescore
  17. 2026-09-16 05:22 UTCGHSA enrichment
  18. 2026-09-15 17:32 UTCEG score recompute
  19. 2026-09-15 16:43 UTCEG score recompute
  20. 2026-09-15 16:42 UTCMITRE cvelistV5first tracked

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-18111?
CVE-2026-18111 is a high vulnerability published on September 15, 2026. Concrete CMS 9 before 9.5.3 was vulnerable to stored cross-site scripting (XSS) in the Feature, Feature Link, Hero Image, and Image blocks and before Concrete 8.5.21 in the feature and Image blocks because the external link URL was insufficiently validated by the link filter and was rendered…
When was CVE-2026-18111 disclosed?
CVE-2026-18111 was first published in the National Vulnerability Database on September 15, 2026, with the most recent update on September 16, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-18111 actively exploited?
CVE-2026-18111 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 76.7% of all scored CVEs.
What is the CVSS score of CVE-2026-18111?
CVE-2026-18111 has a CVSS v3 base score of 8.5 (NVD).
How do I remediate CVE-2026-18111?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-18111, 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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