CVE-2026-85386

MEDIUMNVD 6.16.1—
EchelonGraph scoreHIGH confidence

Score 6.1 from GitHub Security Advisory (severity: HIGH) published 2026-09-16. NVD baseline CVSS 6.1; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, nvd
Trending — 4 sources updated this week
6.1EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 6.1Exploit: None knownExposed: 0

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

Concrete CMS before 9.5.4 did not sanitize XML and XSLT documents uploaded through a public Form Block file-upload question. Plain XML uploads were validated by file extension only and stored as publicly accessible files that were served inline from the application's own origin. An unauthenticated visitor could therefore store an XML document containing an xml-stylesheet processing instruction that referenced an attacker-supplied, same-origin XSLT stylesheet. When a victim opened the stored file directly in a browser, the browser fetched the stylesheet, transformed the document into HTML, and executed attacker-controlled JavaScript in the Concrete CMS origin (stored cross-site scripting). If the victim was an authenticated administrator, the script could act with that administrator's session, and the reporter demonstrated creation of a new user in the Administrators group. 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:L/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N. Thanks Valentin SARRE (Independent security researcher) for reporting.

CVSS v3
6.1
EG Score
6.1(high)
EG Risk
28(Track)
EG Risk 28/100SSVC: 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
Severity61% × 45%
Exploitation0% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
13%
KEV
Not listed

Published

September 16, 2026

Last Modified

September 21, 2026

References (1)

Vendor Advisories for CVE-2026-85386(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 24× in last 7d / 36× 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 14:04 UTCEPSS rescore
  2. 2026-09-24 12:31 UTCEG score recompute
  3. 2026-09-24 12:31 UTCGHSA enrichment
  4. 2026-09-23 17:54 UTCEPSS rescore
  5. 2026-09-23 14:18 UTCGHSA enrichment
  6. 2026-09-22 16:07 UTCEG score recompute
  7. 2026-09-22 16:07 UTCGHSA enrichment
  8. 2026-09-22 16:01 UTCEPSS rescore
  9. 2026-09-21 21:09 UTCEPSS rescore
  10. 2026-09-21 17:55 UTCEG score recompute▼ 1.20
  11. 2026-09-21 17:55 UTCGHSA enrichment
  12. 2026-09-21 17:55 UTCNVD updateCVSS v3 → 6.1 · severity → MEDIUM
  13. 2026-09-21 13:24 UTCGHSA enrichment
  14. 2026-09-21 02:03 UTCEG score recompute
  15. 2026-09-21 02:03 UTCGHSA enrichment
  16. 2026-09-20 20:16 UTCEPSS rescore
  17. 2026-09-20 14:42 UTCGHSA enrichment
  18. 2026-09-20 03:17 UTCGHSA enrichment
  19. 2026-09-19 15:56 UTCEG score recompute
  20. 2026-09-19 15:56 UTCGHSA enrichment
  21. 2026-09-19 04:31 UTCEG score recompute
  22. 2026-09-19 04:31 UTCGHSA enrichment
  23. 2026-09-18 19:28 UTCEPSS rescore
  24. 2026-09-18 17:09 UTCGHSA enrichment
  25. 2026-09-18 05:47 UTCEG score recompute
Show 11 more
  1. 2026-09-18 05:47 UTCGHSA enrichment
  2. 2026-09-17 19:32 UTCEPSS rescore
  3. 2026-09-17 18:26 UTCEG score recompute
  4. 2026-09-17 18:26 UTCGHSA enrichment
  5. 2026-09-17 18:00 UTCEG score recompute
  6. 2026-09-17 18:00 UTCGHSA enrichment
  7. 2026-09-17 06:46 UTCGHSA enrichment
  8. 2026-09-16 19:25 UTCGHSA enrichment
  9. 2026-09-16 17:29 UTCEG score recompute
  10. 2026-09-16 16:46 UTCEG score recompute
  11. 2026-09-16 16:44 UTCMITRE cvelistV5first tracked

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-85386?
CVE-2026-85386 is a medium vulnerability published on September 16, 2026. Concrete CMS before 9.5.4 did not sanitize XML and XSLT documents uploaded through a public Form Block file-upload question. Plain XML uploads were validated by file extension only and stored as publicly accessible files that were served inline from the application's own origin. An unauthenticated…
When was CVE-2026-85386 disclosed?
CVE-2026-85386 was first published in the National Vulnerability Database on September 16, 2026, with the most recent update on September 21, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-85386 actively exploited?
CVE-2026-85386 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 87.0% of all scored CVEs.
What is the CVSS score of CVE-2026-85386?
CVE-2026-85386 has a CVSS v3 base score of 6.1 (NVD).
How do I remediate CVE-2026-85386?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-85386, 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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