Concrete CMS 9 (9.0.0 through 9.5.2) does not perform an authorization check on the user selector autocomplete endpoint (/ccm/system/user/autocomplete), which backs the "Preview as User" panel and other user-selector components. The endpoint validates only a CSRF-style access token that is bound to the selector's display options rather than to the caller's identity or permissions, and that token is issued to anonymous visitors because the selector renders without an authorization check. Because an empty query resolves to a match-all filter, an unauthenticated attacker can submit an empty search and paginate the results to enumerate every backend account, disclosing the internal user ID, username, and email address of all administrative users, including the super-administrator (user ID 1). No password hashes or session material are disclosed The Concrete CMS security team gave this vulnerability a CVSS v4.0 score of 8.7 with vector CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N. Thanks thirtythree and YesWeHack for reporting.
CVE-2026-18110
“—” beside the score: it is equal to NVD's CVSS score.
Score 7.5 from GitHub Security Advisory (severity: HIGH) published 2026-09-15. NVD baseline CVSS 7.5; sources differ by 0.0.
Also known asEUVD-2026-78830 (ENISA EUVD) · GHSA-7hmf-f7jv-m4xw (GitHub Security Advisories)Source: ENISA EUVD
- High severity, but no confirmed exploitation yet
No fix is confirmed yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for the fix.
The CVE record's description, written by its CNA (Concrete CMS), states the affected versions: "Concrete CMS 9 (9.0.0 through 9.5.2) does not perform an authorization check on the user selector autocomplete endpoint (/ccm/system/user/autocomplete), which backs the "Preview as User" panel and other user-selector co…" No release containing a fix is confirmed on record.
- CVSS v3
- 7.5
- EG Score
- 7.5HIGHmedium confidence
- EG Risk
- 49EG Risk 49/100
EG Risk is EchelonGraph's 0–100 priority score. It fuses impact severity (EG Severity, the CVSS base score, never the KEV-floored or EPSS-lifted EG Score) with real-world exploitation and automatability, under weights EchelonGraph set by hand, so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner.
How it’s computed (value × EchelonGraph’s weight)Severity75% × 45%Impact severity (EG Severity): CVSS 7.5 of 10. Never the KEV-floored or EPSS-lifted EG Score.Exploitation1.6% × 40%FIRST EPSS: the 30-day exploitation probability when EchelonGraph scored this CVE.Automatability100% × 15%CISA's SSVC Automatable value: yes (Vulnrichment).SSVC (CISA's decision table, applied by EchelonGraph): Track at low or medium mission impact; Attend at high (mission-essential systems).Exploitation none (CISA Vulnrichment) · Automatable yes (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE.Action: No fix is confirmed yet. Check the vendor's advisory for a fixed release; until one is applied, restrict network exposure of the affected system or apply the vendor's mitigation on your normal schedule at low or medium mission impact and sooner than that at high. - EPSS PROB
- 1.6%
- EPSS %ILE
- 75th
- KEV
- Not listed
What the EG score is made of (scorer v4.0: the three questions the 0–10 score mixes, published apart · methodology)
The EG score (7.5): severity, escalated by confirmed exploitation. This CVE's 7.5 is its impact severity (EG Severity), not escalated.
- EG Severity
- 7.5 HIGHCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.GitHub Security Advisory CVSS
- EG Likelihood
- 1.6% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-10-29). FIRST's exploitation probability, not an EchelonGraph model.
- Confirmed exploitation
- None on record (CISA KEV, EG-KEV Tier 1)Reported apart from the likelihood: an observed fact, not a probability.
- EG Priority
- SSVC Track at medium mission impactTrack at low or medium mission impact; Attend at high (mission-essential systems).CISA BOD 26-04: 14 days if the affected system is publicly exposed; 60 days if it is not.No released fix is confirmed on this page, but CISA's timeline does not wait for a fix's release: it starts when an agency identifies the flaw on an asset and updates the CDM Agency and Federal Dashboard, and the directive counts patching, decommissioning the system or another action as remediation. Until a fixed release is applied, mitigate as this page's verdict says.Each input and its source, and whom BOD 26-04 binds: the SSVC and BOD 26-04 blocks below.
SSVC (CISA's decision table, applied by EchelonGraph)Track at low or medium mission impact; Attend at high (mission-essential systems).
No fix is confirmed yet. Check the vendor's advisory for a fixed release; until one is applied, restrict network exposure of the affected system or apply the vendor's mitigation on your normal schedule at low or medium mission impact and sooner than that at high.
Exploitation none (CISA Vulnrichment) · Automatable yes (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE. Mission impact is CISA's Mission & Well-being decision point, and only you can judge it. CISA's table makes it high when Mission Prevalence is Essential — the vulnerable component "directly provides capabilities that constitute at least one MEF for at least one entity" (MEF: mission essential function) — or when Public Well-Being Impact is Irreversible: "multiple fatalities are likely", the cyber-physical system "is likely lost or destroyed", "extreme or serious externalities" are imposed on other parties, or social systems such as elections or the financial grid "are destabilized and potentially collapse". CISA's decision table
BOD 26-04 (CISA's remediation timeline, Table 1)14 days if the affected system is publicly exposed; 60 days if it is not.
No released fix is confirmed on this page, but CISA's timeline does not wait for a fix's release: it starts when an agency identifies the flaw on an asset and updates the CDM Agency and Federal Dashboard, and the directive counts patching, decommissioning the system or another action as remediation. Until a fixed release is applied, mitigate as this page's verdict says.
The score's inputs: In CISA KEV no (CISA's KEV catalog) · Automatable yes (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). Whether your system is publicly exposed is yours to answer. BOD 26-04 binds US Federal Civilian Executive Branch agencies; for anyone else it is CISA's published timeline, a reference rather than an obligation. The directive · how EchelonGraph applies it
Published
September 15, 2026
Last Modified
September 22, 2026
References (1)
Vendor Advisories for CVE-2026-18110(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 9× in last 7d / 66× in last 30d)
Each row is a time one of our pipelines fetched, updated or re-scored this CVE. 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. An arrow marks a change the record states ("CVSS v3 → 9.1"); EPSS and GHSA rows show the values recorded at that time, not what changed (EPSS values are rounded; hover one for the exact figures). Most recent first.
Showing the most recent 100 of 137 refreshes on record for this CVE.
A repeat, a row identical to one the same pipeline wrote less than 10 seconds earlier, is not a separate refresh and is not counted. None are among the latest 100 rows. The 37 oldest rows on record are not shown and were not checked, so the counts can still include repeats.
- 2026-11-01 16:34 UTCEPSS rescoreEPSS 1.6% · 75th percentile
- 2026-10-31 16:32 UTCEPSS rescoreEPSS 1.6% · 75th percentile
- 2026-10-30 16:33 UTCEPSS rescoreEPSS 1.6% · 75th percentile
- 2026-10-30 10:37 UTCEG score recompute
- 2026-10-30 10:37 UTCGHSA enrichmentGHSA-7hmf-f7jv-m4xw · GitHub severity HIGH · GitHub CVSS 7.5
- 2026-10-29 16:32 UTCEPSS rescoreEPSS 1.6% · 75th percentile
- 2026-10-28 16:31 UTCEPSS rescoreEPSS 1.6% · 75th percentile
- 2026-10-27 16:31 UTCEPSS rescoreEPSS 1.6% · 75th percentile
- 2026-10-26 16:31 UTCEPSS rescoreEPSS 1.6% · 75th percentile
- 2026-10-25 16:32 UTCEPSS rescoreEPSS 1.6% · 75th percentile
- 2026-10-25 14:45 UTCEG score recompute
- 2026-10-24 16:32 UTCEPSS rescoreEPSS 0.3% · 17th percentile
- 2026-10-23 16:31 UTCEPSS rescoreEPSS 0.3% · 17th percentile
- 2026-10-23 02:39 UTCEG score recompute
- 2026-10-23 02:39 UTCGHSA enrichmentGHSA-7hmf-f7jv-m4xw · GitHub severity HIGH · GitHub CVSS 7.5
- 2026-10-22 16:34 UTCEPSS rescoreEPSS 0.3% · 17th percentile
- 2026-10-21 16:32 UTCEPSS rescoreEPSS 0.3% · 17th percentile
- 2026-10-20 16:32 UTCEPSS rescoreEPSS 0.3% · 17th percentile
- 2026-10-19 16:31 UTCEPSS rescoreEPSS 0.3% · 17th percentile
- 2026-10-18 16:31 UTCEPSS rescoreEPSS 0.3% · 17th percentile
- 2026-10-18 03:59 UTCEG score recompute
- 2026-10-17 16:33 UTCEPSS rescoreEPSS 0.3% · 17th percentile
- 2026-10-16 16:40 UTCEPSS rescoreEPSS 0.3% · 17th percentile
- 2026-10-15 18:36 UTCEG score recompute
- 2026-10-15 18:36 UTCGHSA enrichmentGHSA-7hmf-f7jv-m4xw · GitHub severity HIGH · GitHub CVSS 7.5
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- 2026-10-15 16:31 UTCEPSS rescoreEPSS 0.3% · 17th percentile
- 2026-10-14 16:32 UTCEPSS rescoreEPSS 0.3% · 17th percentile
- 2026-10-13 16:33 UTCEPSS rescoreEPSS 0.3% · 17th percentile
- 2026-10-12 16:33 UTCEPSS rescoreEPSS 0.3% · 17th percentile
- 2026-10-12 16:28 UTCEG score recompute
- 2026-10-11 19:31 UTCEG score recompute
- 2026-10-11 19:30 UTCGHSA enrichmentGHSA-7hmf-f7jv-m4xw · GitHub severity HIGH · GitHub CVSS 7.5
- 2026-10-11 17:20 UTCEG score recompute
- 2026-10-11 14:52 UTCEG score recompute
- 2026-10-11 13:48 UTCEPSS rescoreEPSS 0.3% · 17th percentile
- 2026-10-11 05:38 UTCEG score recompute
- 2026-10-11 05:38 UTCGHSA enrichmentGHSA-7hmf-f7jv-m4xw · GitHub severity HIGH · GitHub CVSS 7.5
- 2026-10-10 19:59 UTCEPSS rescoreEPSS 0.3% · 17th percentile
- 2026-10-10 15:22 UTCGHSA enrichmentGHSA-7hmf-f7jv-m4xw · GitHub severity HIGH · GitHub CVSS 7.5
- 2026-10-10 03:34 UTCEG score recompute
- 2026-10-10 03:34 UTCGHSA enrichmentGHSA-7hmf-f7jv-m4xw · GitHub severity HIGH · GitHub CVSS 7.5
- 2026-10-09 20:06 UTCEPSS rescoreEPSS 0.3% · 17th percentile
- 2026-10-09 15:50 UTCGHSA enrichmentGHSA-7hmf-f7jv-m4xw · GitHub severity HIGH · GitHub CVSS 7.5
- 2026-10-08 22:37 UTCEG score recompute
- 2026-10-08 22:37 UTCGHSA enrichmentGHSA-7hmf-f7jv-m4xw · GitHub severity HIGH · GitHub CVSS 7.5
- 2026-10-08 17:11 UTCEPSS rescoreEPSS 0.3% · 17th percentile
- 2026-10-08 06:37 UTCEG score recompute
- 2026-10-08 06:37 UTCGHSA enrichmentGHSA-7hmf-f7jv-m4xw · GitHub severity HIGH · GitHub CVSS 7.5
- 2026-10-07 23:47 UTCEPSS rescoreEPSS 0.3% · 17th percentile
- 2026-10-07 18:52 UTCGHSA enrichmentGHSA-7hmf-f7jv-m4xw · GitHub severity HIGH · GitHub CVSS 7.5
- 2026-10-07 03:51 UTCGHSA enrichmentGHSA-7hmf-f7jv-m4xw · GitHub severity HIGH · GitHub CVSS 7.5
- 2026-10-06 16:06 UTCEG score recompute
- 2026-10-06 16:06 UTCGHSA enrichmentGHSA-7hmf-f7jv-m4xw · GitHub severity HIGH · GitHub CVSS 7.5
- 2026-10-06 15:17 UTCEPSS rescoreEPSS 0.3% · 17th percentile
- 2026-10-06 04:21 UTCEG score recompute
- 2026-10-06 04:21 UTCGHSA enrichmentGHSA-7hmf-f7jv-m4xw · GitHub severity HIGH · GitHub CVSS 7.5
- 2026-10-05 17:42 UTCEPSS rescoreEPSS 0.3% · 17th percentile
- 2026-10-05 16:14 UTCGHSA enrichmentGHSA-7hmf-f7jv-m4xw · GitHub severity HIGH · GitHub CVSS 7.5
- 2026-10-05 03:30 UTCEG score recompute
- 2026-10-05 03:30 UTCGHSA enrichmentGHSA-7hmf-f7jv-m4xw · GitHub severity HIGH · GitHub CVSS 7.5
- 2026-10-04 23:21 UTCEPSS rescoreEPSS 0.3% · 17th percentile
- 2026-10-04 15:45 UTCGHSA enrichmentGHSA-7hmf-f7jv-m4xw · GitHub severity HIGH · GitHub CVSS 7.5
- 2026-10-04 04:00 UTCGHSA enrichmentGHSA-7hmf-f7jv-m4xw · GitHub severity HIGH · GitHub CVSS 7.5
- 2026-10-03 16:15 UTCEG score recompute
- 2026-10-03 16:15 UTCGHSA enrichmentGHSA-7hmf-f7jv-m4xw · GitHub severity HIGH · GitHub CVSS 7.5
- 2026-10-03 14:25 UTCEPSS rescoreEPSS 0.3% · 17th percentile
- 2026-10-03 04:31 UTCGHSA enrichmentGHSA-7hmf-f7jv-m4xw · GitHub severity HIGH · GitHub CVSS 7.5
- 2026-10-02 16:46 UTCEG score recompute
- 2026-10-02 16:46 UTCGHSA enrichmentGHSA-7hmf-f7jv-m4xw · GitHub severity HIGH · GitHub CVSS 7.5
- 2026-10-02 05:02 UTCEG score recompute
- 2026-10-02 05:02 UTCGHSA enrichmentGHSA-7hmf-f7jv-m4xw · GitHub severity HIGH · GitHub CVSS 7.5
- 2026-10-01 19:49 UTCEPSS rescoreEPSS 0.3% · 17th percentile
- 2026-10-01 17:08 UTCGHSA enrichmentGHSA-7hmf-f7jv-m4xw · GitHub severity HIGH · GitHub CVSS 7.5
- 2026-10-01 05:00 UTCGHSA enrichmentGHSA-7hmf-f7jv-m4xw · GitHub severity HIGH · GitHub CVSS 7.5
- 2026-09-30 17:04 UTCEG score recompute
- 2026-09-30 17:04 UTCGHSA enrichmentGHSA-7hmf-f7jv-m4xw · GitHub severity HIGH · GitHub CVSS 7.5
- 2026-09-30 15:02 UTCEPSS rescoreEPSS 0.3% · 17th percentile
- 2026-09-30 04:48 UTCGHSA enrichmentGHSA-7hmf-f7jv-m4xw · GitHub severity HIGH · GitHub CVSS 7.5
- 2026-09-29 16:53 UTCEG score recompute
- 2026-09-29 16:53 UTCGHSA enrichmentGHSA-7hmf-f7jv-m4xw · GitHub severity HIGH · GitHub CVSS 7.5
- 2026-09-29 15:20 UTCEPSS rescoreEPSS 0.3% · 16th percentile
- 2026-09-29 04:51 UTCEG score recompute
- 2026-09-29 04:51 UTCGHSA enrichmentGHSA-7hmf-f7jv-m4xw · GitHub severity HIGH · GitHub CVSS 7.5
- 2026-09-28 17:07 UTCEG score recompute
- 2026-09-28 17:07 UTCGHSA enrichmentGHSA-7hmf-f7jv-m4xw · GitHub severity HIGH · GitHub CVSS 7.5
- 2026-09-28 13:51 UTCEPSS rescoreEPSS 0.3% · 16th percentile
- 2026-09-28 05:17 UTCGHSA enrichmentGHSA-7hmf-f7jv-m4xw · GitHub severity HIGH · GitHub CVSS 7.5
- 2026-09-27 17:33 UTCEG score recompute
- 2026-09-27 17:33 UTCGHSA enrichmentGHSA-7hmf-f7jv-m4xw · GitHub severity HIGH · GitHub CVSS 7.5
- 2026-09-27 13:47 UTCEPSS rescoreEPSS 0.3% · 16th percentile
- 2026-09-27 05:48 UTCGHSA enrichmentGHSA-7hmf-f7jv-m4xw · GitHub severity HIGH · GitHub CVSS 7.5
- 2026-09-26 18:02 UTCEG score recompute
- 2026-09-26 18:02 UTCGHSA enrichmentGHSA-7hmf-f7jv-m4xw · GitHub severity HIGH · GitHub CVSS 7.5
- 2026-09-26 15:58 UTCEPSS rescoreEPSS 0.3% · 16th percentile
- 2026-09-26 06:17 UTCEG score recompute
- 2026-09-26 06:17 UTCGHSA enrichmentGHSA-7hmf-f7jv-m4xw · GitHub severity HIGH · GitHub CVSS 7.5
- 2026-09-25 18:30 UTCGHSA enrichmentGHSA-7hmf-f7jv-m4xw · GitHub severity HIGH · GitHub CVSS 7.5
- 2026-09-25 05:55 UTCGHSA enrichmentGHSA-7hmf-f7jv-m4xw · GitHub severity HIGH · GitHub CVSS 7.5
- 2026-09-24 18:10 UTCEG score recompute
- 2026-09-24 18:10 UTCGHSA enrichmentGHSA-7hmf-f7jv-m4xw · GitHub severity HIGH · GitHub CVSS 7.5
Public detection templates
(1 reference)A public Nuclei detection template is referenced for this CVE. A detection template checks whether a system is affected; it is not necessarily exploit code.
- Nucleihttp/cves/2026/CVE-2026-18110.yamlRecorded Oct 24, 2026
Concrete CMS - User Enumeration
Open source ↗
Related CVEs(same CWE)
Frequently asked(5)
What is CVE-2026-18110?
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What is the CVSS score of CVE-2026-18110?
How do I remediate CVE-2026-18110?
Dependency Blast Radius
Explore the affected products and dependency analysis for CVE-2026-18110
Is Your Infrastructure Affected by CVE-2026-18110?
EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.