CVE-2026-81909

MEDIUMPre-NVD 5.95.9—
EchelonGraph scoreMEDIUM confidence

This medium-severity CVE scores 5.9 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.4%, top 64% 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 — 3 sources updated this week
5.9EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 5.9Exploit: None knownExposed: 0

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

Concrete CMS 9 through 9.5.2 is vulnerable to Missing Authorization in the block alias route (Process::alias() in concrete/controllers/backend/block/process.php).It does not verify that the referenced block is genuinely orphaned on the target page, nor that the caller holds any permission over the source block. A user granted only an area-scoped add_block_to_area delegation on their own page can therefore pass any block ID on the site: the source block's content is duplicated into an area the rogue editor controls, disclosing that content, and the original block is then force-deleted in the same request, destroying arbitrary site content. The Concrete CMS security team gave this vulnerability a CVSS v4.0 score of 5.9 with vector CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:N/VC:N/VI:H/VA:H/SC:N/SI:N/SA:N. Thanks Yonatan Drori from Tenzai for reporting.

CVSS v3
5.9
EG Score
5.9(medium)
EG Risk
27(Track)
EG Risk 27/100SSVC: 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
Severity59% × 45%
Exploitation0% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
36%
KEV
Not listed

Published

September 11, 2026

Last Modified

September 11, 2026

References (1)

Vendor Advisories for CVE-2026-81909(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 / 42× 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. 2026-09-24 23:18 UTCEG score recompute
  2. 2026-09-24 23:18 UTCGHSA enrichment
  3. 2026-09-24 14:04 UTCEPSS rescore
  4. 2026-09-24 00:42 UTCEG score recompute
  5. 2026-09-24 00:42 UTCGHSA enrichment
  6. 2026-09-23 17:54 UTCEPSS rescore
  7. 2026-09-23 02:07 UTCEG score recompute
  8. 2026-09-23 02:07 UTCGHSA enrichment
  9. 2026-09-22 16:01 UTCEPSS rescore
  10. 2026-09-22 03:32 UTCEG score recompute
  11. 2026-09-22 03:32 UTCGHSA enrichment
  12. 2026-09-21 21:09 UTCEPSS rescore
  13. 2026-09-21 04:56 UTCEG score recompute
  14. 2026-09-21 04:56 UTCGHSA enrichment
  15. 2026-09-20 20:16 UTCEPSS rescore
  16. 2026-09-20 05:58 UTCEG score recompute
  17. 2026-09-20 05:58 UTCGHSA enrichment
  18. 2026-09-19 07:22 UTCEG score recompute
  19. 2026-09-19 07:22 UTCGHSA enrichment
  20. 2026-09-18 19:28 UTCEPSS rescore
  21. 2026-09-18 08:47 UTCEG score recompute
  22. 2026-09-18 08:47 UTCGHSA enrichment
  23. 2026-09-17 10:12 UTCEG score recompute
  24. 2026-09-17 10:12 UTCGHSA enrichment
  25. 2026-09-16 14:08 UTCEPSS rescore
Show 17 more
  1. 2026-09-16 11:37 UTCEG score recompute
  2. 2026-09-16 11:36 UTCGHSA enrichment
  3. 2026-09-16 05:15 UTCEPSS rescore
  4. 2026-09-15 12:56 UTCEG score recompute
  5. 2026-09-15 12:56 UTCGHSA enrichment
  6. 2026-09-15 03:12 UTCEPSS rescore
  7. 2026-09-15 03:12 UTCEPSS rescore
  8. 2026-09-14 14:21 UTCEG score recompute
  9. 2026-09-14 14:21 UTCGHSA enrichment
  10. 2026-09-13 15:45 UTCGHSA enrichment
  11. 2026-09-12 17:09 UTCEG score recompute
  12. 2026-09-12 17:09 UTCGHSA enrichment
  13. 2026-09-11 18:34 UTCEG score recompute
  14. 2026-09-11 18:34 UTCGHSA enrichment
  15. 2026-09-11 18:04 UTCEG score recompute
  16. 2026-09-11 17:54 UTCEG score recompute
  17. 2026-09-11 17:53 UTCMITRE cvelistV5first tracked

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-81909?
CVE-2026-81909 is a medium vulnerability published on September 11, 2026. Concrete CMS 9 through 9.5.2 is vulnerable to Missing Authorization in the block alias route (Process::alias() in concrete/controllers/backend/block/process.php).It does not verify that the referenced block is genuinely orphaned on the target page, nor that the caller holds any permission over the…
When was CVE-2026-81909 disclosed?
CVE-2026-81909 was first published in the National Vulnerability Database on September 11, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-81909 actively exploited?
CVE-2026-81909 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 64.4% of all scored CVEs.
What is the CVSS score of CVE-2026-81909?
CVE-2026-81909 has a CVSS v3 base score of 5.9 (NVD).
How do I remediate CVE-2026-81909?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-81909, 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

Explore the affected products and dependency analysis for CVE-2026-81909

Explore →

Is Your Infrastructure Affected by CVE-2026-81909?

EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.

Book a Demo →Browse All CVEs