CVE-2026-81913

MEDIUMPre-NVD 5.35.3—
EchelonGraph scoreMEDIUM confidence

This medium-severity CVE scores 5.3 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.6%, top 53% 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
5.3EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 1%CVSS: 5.3Exploit: None knownExposed: 0

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

Concrete CMS versions 9.5.0 through 9.5.2 are vulnerable to Open Redirect via the rcURL parameter. An attacker can craft a single link on the site's own domain that sends a user to an arbitrary external site immediately after authentication, facilitating phishing and credential theft. The same handling is present in the registration flow, giving a second entry point on sites with registration enabled. Concrete CMS versions prior to 9.5.0 do not include the rcURL parameter or this allowlist and are not affected. The Concrete CMS security team gave this vulnerability a CVSS v4.0 score of 5.3 with vector CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N. Thanks Michal M. for reporting.

CVSS v3
5.3
EG Score
5.3(medium)
EG Risk
29(Track)
EG Risk 29/100SSVC: 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
Severity53% × 45%
Exploitation1% × 40%
Automatability30% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
1%
EPSS %ILE
47%
KEV
Not listed

Published

September 11, 2026

Last Modified

September 15, 2026

References (1)

Vendor Advisories for CVE-2026-81913(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 / 27× 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 20:16 UTCEPSS rescore
  2. 2026-09-20 07:15 UTCEG score recompute
  3. 2026-09-20 07:15 UTCGHSA enrichment
  4. 2026-09-19 08:56 UTCEG score recompute
  5. 2026-09-19 08:55 UTCGHSA enrichment
  6. 2026-09-18 19:28 UTCEPSS rescore
  7. 2026-09-18 10:36 UTCEG score recompute
  8. 2026-09-18 10:35 UTCGHSA enrichment
  9. 2026-09-17 12:12 UTCEG score recompute
  10. 2026-09-17 12:12 UTCGHSA enrichment
  11. 2026-09-16 14:08 UTCEPSS rescore
  12. 2026-09-16 13:52 UTCEG score recompute
  13. 2026-09-16 13:51 UTCGHSA enrichment
  14. 2026-09-16 05:15 UTCEPSS rescore
  15. 2026-09-15 15:02 UTCGHSA enrichment
  16. 2026-09-15 14:04 UTCEG score recompute
  17. 2026-09-15 14:04 UTCGHSA enrichment
  18. 2026-09-15 03:12 UTCEPSS rescore
  19. 2026-09-15 03:12 UTCEPSS rescore
  20. 2026-09-14 15:44 UTCGHSA enrichment
  21. 2026-09-13 17:25 UTCEG score recompute
  22. 2026-09-13 17:25 UTCGHSA enrichment
  23. 2026-09-12 19:06 UTCEG score recompute
  24. 2026-09-12 19:06 UTCGHSA enrichment
  25. 2026-09-11 20:46 UTCEG score recompute
Show 2 more
  1. 2026-09-11 19:34 UTCEG score recompute
  2. 2026-09-11 19:33 UTCMITRE cvelistV5first tracked

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-81913?
CVE-2026-81913 is a medium vulnerability published on September 11, 2026. Concrete CMS versions 9.5.0 through 9.5.2 are vulnerable to Open Redirect via the rcURL parameter. An attacker can craft a single link on the site's own domain that sends a user to an arbitrary external site immediately after authentication, facilitating phishing and credential theft. The same…
When was CVE-2026-81913 disclosed?
CVE-2026-81913 was first published in the National Vulnerability Database on September 11, 2026, with the most recent update on September 15, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-81913 actively exploited?
CVE-2026-81913 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 1% probability of exploitation in the next 30 days, which ranks it in the top 53.1% of all scored CVEs.
What is the CVSS score of CVE-2026-81913?
CVE-2026-81913 has a CVSS v3 base score of 5.3 (NVD).
How do I remediate CVE-2026-81913?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-81913, 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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