CVE-2026-81899

HIGHPre-NVD 7.37.3—
EchelonGraph scoreMEDIUM confidence

This high-severity CVE scores 7.3 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.5%, top 61% 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
7.3EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 7.3Exploit: None knownExposed: 0

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

Concrete CMS 9.0.0 to 9.5.2 stored group folder names without sanitization and printed them unescaped on the Members > Groups dashboard page, resulting in stored cross-site scripting. The add and edit group-folder handlers stored the submitted folder name without neutralizing HTML, and the group search grid returned it without output encoding, so the Groups dashboard rendered the name as live markup. An authenticated user holding the Add Group Folder permission could store a script payload as a folder name that executed in the session of any administrator who viewed the Groups dashboard, enabling session and token theft and any action available in the administrator's context. The Concrete CMS security team gave this vulnerability a CVSS v4.0 score of 7.3 with vector CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N. Thanks Lý Chấn Hưng (hunglyvn) for reporting.

CVSS v3
7.3
EG Score
7.3(medium)
EG Risk
33(Track)
EG Risk 33/100SSVC: 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
Severity73% × 45%
Exploitation0% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
39%
KEV
Not listed

Published

September 15, 2026

Last Modified

September 16, 2026

References (1)

Vendor Advisories for CVE-2026-81899(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 26× in last 7d / 41× 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 08:01 UTCGHSA enrichment
  2. 2026-09-24 20:00 UTCEG score recompute
  3. 2026-09-24 20:00 UTCGHSA enrichment
  4. 2026-09-24 14:04 UTCEPSS rescore
  5. 2026-09-24 07:59 UTCGHSA enrichment
  6. 2026-09-23 19:58 UTCEG score recompute
  7. 2026-09-23 19:58 UTCGHSA enrichment
  8. 2026-09-23 17:54 UTCEPSS rescore
  9. 2026-09-23 07:57 UTCGHSA enrichment
  10. 2026-09-22 19:56 UTCEG score recompute
  11. 2026-09-22 19:56 UTCGHSA enrichment
  12. 2026-09-22 16:01 UTCEPSS rescore
  13. 2026-09-22 07:54 UTCEG score recompute
  14. 2026-09-22 07:54 UTCGHSA enrichment
  15. 2026-09-21 21:09 UTCEPSS rescore
  16. 2026-09-21 19:53 UTCGHSA enrichment
  17. 2026-09-21 07:52 UTCEG score recompute
  18. 2026-09-21 07:52 UTCGHSA enrichment
  19. 2026-09-20 20:16 UTCEPSS rescore
  20. 2026-09-20 19:51 UTCGHSA enrichment
  21. 2026-09-20 07:50 UTCGHSA enrichment
  22. 2026-09-19 19:33 UTCGHSA enrichment
  23. 2026-09-19 07:32 UTCGHSA enrichment
  24. 2026-09-18 19:31 UTCEG score recompute
  25. 2026-09-18 19:31 UTCGHSA enrichment
Show 16 more
  1. 2026-09-18 19:28 UTCEPSS rescore
  2. 2026-09-18 07:30 UTCEG score recompute
  3. 2026-09-18 07:30 UTCGHSA enrichment
  4. 2026-09-17 19:29 UTCGHSA enrichment
  5. 2026-09-17 07:25 UTCGHSA enrichment
  6. 2026-09-16 19:24 UTCEG score recompute
  7. 2026-09-16 19:23 UTCGHSA enrichment
  8. 2026-09-16 14:08 UTCEPSS rescore
  9. 2026-09-16 08:47 UTCGHSA enrichment
  10. 2026-09-15 20:42 UTCEG score recompute
  11. 2026-09-15 20:42 UTCGHSA enrichment
  12. 2026-09-15 19:23 UTCEG score recompute
  13. 2026-09-15 19:23 UTCGHSA enrichment
  14. 2026-09-15 18:32 UTCEG score recompute
  15. 2026-09-15 18:04 UTCEG score recompute
  16. 2026-09-15 18:02 UTCMITRE cvelistV5first tracked

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Frequently asked(5)

What is CVE-2026-81899?
CVE-2026-81899 is a high vulnerability published on September 15, 2026. Concrete CMS 9.0.0 to 9.5.2 stored group folder names without sanitization and printed them unescaped on the Members > Groups dashboard page, resulting in stored cross-site scripting. The add and edit group-folder handlers stored the submitted folder name without neutralizing HTML, and the group…
When was CVE-2026-81899 disclosed?
CVE-2026-81899 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-2026-81899 actively exploited?
CVE-2026-81899 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 61.1% of all scored CVEs.
What is the CVSS score of CVE-2026-81899?
CVE-2026-81899 has a CVSS v3 base score of 7.3 (NVD).
How do I remediate CVE-2026-81899?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-81899, 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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