CVE-2026-81901

HIGHNVD 8.78.7—
EchelonGraph scoreHIGH confidence

Score 8.7 from GitHub Security Advisory (severity: HIGH) published 2026-09-14. NVD baseline CVSS 8.7; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, nvd
Trending — 4 sources updated this week
8.7EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 8.7Exploit: None knownExposed: 0

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

In Concrete CMS 9.2.0 through 9.5.2, the REST API page update endpoint (PUT /ccm/api/1.0/pages/{cID}) did not enforce page-property, page-template, or page-type authorization. A user granted only content-editing rights on a page could therefore alter its properties, template, and type through the API, and could set the header_extra_content attribute, which is rendered unescaped into the head element of every page, to persist JavaScript that executed in the browser of every visitor, including higher-privileged reviewers who approve the page version. The Concrete CMS security team gave this vulnerability a CVSS v4.0 score of 7.2 with vector CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:P/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N. Thanks Yonatan Drori from Tenzai for reporting.

CVSS v3
8.7
EG Score
8.7(high)
EG Risk
39(Track)
EG Risk 39/100SSVC: 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
Severity87% × 45%
Exploitation0% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
30%
KEV
Not listed

Published

September 14, 2026

Last Modified

September 18, 2026

References (1)

Vendor Advisories for CVE-2026-81901(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 30× in last 7d / 49× 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. 2026-09-25 08:33 UTCGHSA enrichment
  2. 2026-09-24 20:30 UTCEG score recompute
  3. 2026-09-24 20:30 UTCGHSA enrichment
  4. 2026-09-24 14:04 UTCEPSS rescore
  5. 2026-09-24 08:27 UTCGHSA enrichment
  6. 2026-09-23 20:24 UTCEG score recompute
  7. 2026-09-23 20:24 UTCGHSA enrichment
  8. 2026-09-23 17:54 UTCEPSS rescore
  9. 2026-09-23 08:19 UTCGHSA enrichment
  10. 2026-09-22 20:17 UTCEG score recompute
  11. 2026-09-22 20:17 UTCGHSA enrichment
  12. 2026-09-22 16:01 UTCEPSS rescore
  13. 2026-09-22 08:10 UTCEG score recompute
  14. 2026-09-22 08:10 UTCGHSA enrichment
  15. 2026-09-21 21:09 UTCEPSS rescore
  16. 2026-09-21 20:07 UTCGHSA enrichment
  17. 2026-09-21 08:04 UTCEG score recompute
  18. 2026-09-21 08:04 UTCGHSA enrichment
  19. 2026-09-20 20:16 UTCEPSS rescore
  20. 2026-09-20 20:01 UTCGHSA enrichment
  21. 2026-09-20 07:58 UTCGHSA enrichment
  22. 2026-09-19 19:35 UTCEG score recompute
  23. 2026-09-19 19:35 UTCGHSA enrichment
  24. 2026-09-19 07:33 UTCEG score recompute
  25. 2026-09-19 07:32 UTCGHSA enrichment
Show 24 more
  1. 2026-09-18 19:30 UTCEG score recompute▲ 1.50
  2. 2026-09-18 19:30 UTCGHSA enrichment
  3. 2026-09-18 19:28 UTCEPSS rescore
  4. 2026-09-18 19:26 UTCNVD updateCVSS v3 → 8.7
  5. 2026-09-18 16:09 UTCGHSA enrichment
  6. 2026-09-18 03:47 UTCEG score recompute
  7. 2026-09-18 03:47 UTCGHSA enrichment
  8. 2026-09-17 15:44 UTCGHSA enrichment
  9. 2026-09-17 03:41 UTCGHSA enrichment
  10. 2026-09-16 15:38 UTCEG score recompute
  11. 2026-09-16 15:38 UTCGHSA enrichment
  12. 2026-09-16 14:08 UTCEPSS rescore
  13. 2026-09-16 05:15 UTCEPSS rescore
  14. 2026-09-16 03:35 UTCGHSA enrichment
  15. 2026-09-15 15:32 UTCGHSA enrichment
  16. 2026-09-15 15:01 UTCEG score recompute
  17. 2026-09-15 15:01 UTCGHSA enrichment
  18. 2026-09-15 14:34 UTCEG score recompute
  19. 2026-09-15 14:34 UTCGHSA enrichment
  20. 2026-09-15 09:35 UTCGHSA enrichment
  21. 2026-09-14 21:32 UTCEG score recompute
  22. 2026-09-14 21:32 UTCGHSA enrichment
  23. 2026-09-14 20:45 UTCEG score recompute
  24. 2026-09-14 20:44 UTCMITRE cvelistV5first tracked

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-81901?
CVE-2026-81901 is a high vulnerability published on September 14, 2026. In Concrete CMS 9.2.0 through 9.5.2, the REST API page update endpoint (PUT /ccm/api/1.0/pages/{cID}) did not enforce page-property, page-template, or page-type authorization. A user granted only content-editing rights on a page could therefore alter its properties, template, and type through the…
When was CVE-2026-81901 disclosed?
CVE-2026-81901 was first published in the National Vulnerability Database on September 14, 2026, with the most recent update on September 18, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-81901 actively exploited?
CVE-2026-81901 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 70.5% of all scored CVEs.
What is the CVSS score of CVE-2026-81901?
CVE-2026-81901 has a CVSS v3 base score of 8.7 (NVD).
How do I remediate CVE-2026-81901?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-81901, 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.

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