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CVE-2025-8571· NVD / CVE Program· CNA ConcreteCMS

Concrete CMS 9 through 9.4.2 and below 8.5.21 is vulnerable to Reflected Cross-Site Scripting (XSS) in Conversation Messages Dashboard Page

Concrete CMS 9 to 9.4.2 and versions below 8.5.21 are vulnerable to Reflected Cross-Site Scripting (XSS) in the Conversation Messages Dashboard Page. Unsanitized input could cause theft of session cookies or tokens, defacement of web content, redirection to malicious sites, and (if victim is an admin), the execution of unauthorized actions. The Concrete CMS security team gave this vulnerability a CVSS v.4.0 score of 4.8 with vector CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:P/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N. Thanks Fortbridge https://fortbridge.co.uk/  for performing a penetration test and vulnerability assessment on Concrete CMS and reporting this issue.

MediumCVSS 4.8 · v4.0—Proof of concept Fix available
Published
Aug 5, 2025
Updated
Jun 17, 2026
EPSS
0.3% · 22th percentile
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Report tools

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Action score

19

Monitor

Low priority for now.

CVSS
19 / 40 · 4.8 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.3%

CISA SSVC decision

Exploitation
none
Automatable
no
Technical impact
partial

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD
—
CNA · ConcreteCMS
4.8
NVD has not scored this yet; the score shown is the CNA’s.

CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:P/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

Affected systems

VendorProduct
concretecmsconcrete cms

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • concretecms concrete cmsbefore 8.5.21
  • concretecms concrete cms9.0 and later · before 9.4.3

Versions reported by the vendor

Affected version ranges reported by the assigning authority (ConcreteCMS). Independent of NVD's CPE analysis and usually ahead of it.

  • Concrete CMS Concrete CMS

    • 9.0.0 and later · before 9.4.3affected · patch
    • 5.6 and later · before 8.5.21affected · patch

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
Packagistconcrete5/concrete5from 9.0.0RC1 · before 9.4.39.4.3
Packagistconcrete5/concrete5before 8.5.218.5.21

Same product

concretecms: all records

Other highest-scoring records for the same primary product.

  • CVE-2022-21829Concrete CMS Versions 9.0.0 through 9.0.2 and 8.5.7 and below can download zip files over HTTP and execute code from those zip files which c
    40Plan
  • CVE-2023-48648Concrete CMS before 8.5.13 and 9.x before 9.2.2 allows unauthorized access because directories can be created with insecure permissions.
    39Monitor
  • CVE-2021-22958A Server-Side Request Forgery vulnerability was found in concrete5 < 8.5.5 that allowed a decimal notation encoded IP address to bypass the
    39Monitor
  • CVE-2021-40098An issue was discovered in Concrete CMS through 8.5.5.
    39Monitor
  • CVE-2026-8134Concrete CMS 9.5.0 and below is vulnerable to Authenticated RCE via Composer customTemplate Path Traversal leading to PHP File Inclusion
    37Monitor
  • CVE-2022-30117Concrete 8.5.7 and below as well as Concrete 9.0 through 9.0.2 allow traversal in /index.php/ccm/system/file/upload which could result in an
    37Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
Concrete CMS Concrete CMS8.5.21Vendor (CNA)
Concrete CMS Concrete CMS9.4.3Vendor (CNA)
Packagist:concrete5/concrete58.5.21Package registry (OSV)
Packagist:concrete5/concrete59.4.3Package registry (OSV)

Exploit status

Proof of concept available

A public proof of concept or detection signature exists. Exploit knowledge is out there; don't delay patching.

Evidence

  • Proof-of-concept repository on GitHub ×1

Noroxi does not host or link to exploit code. Metasploit module names and Nuclei template ids are shown (names, not code); Exploit-DB entries and PoC repositories are given as counts only.

Public exploit evidence
SourceKindDate
Proof-of-concept repository on GitHubstars:02025-09-12

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

  1. Published
  2. First PoC+37 d
  3. TodaySep 30, 2026+421 d
EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

  • CVE-2025-0660148 days apartStored XSS in Folder Function by Rogue Admin
    19Monitor
  • CVE-2024-7512358 days apartConcrete CMS Stored XSS in Board instances
    18Monitor
  • CVE-2024-4353369 days apartStored XSS in Generate Board Name Input Field
    18Monitor
  • CVE-2025-85730 days apartConcrete CMS 9 through 9.4.2 is vulnerable to Stored XSS from Home Folder on Members Dashboard page
    8Monitor

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

The product’s vendor appears in a public program. Matched by name; verify the scope text in the program.

Technical details

Attack conditions

  • Anyone who can reach it over the internet can trigger it.
  • Administrator privileges are required.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
Integrity
Availability
Attack vector
Network
Attack complexity
Low
Privileges required
High
User interaction
P
Scope
X

Weakness class (CWE)

CWE-20 · Improper Input Validation

CVSS vector

CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:P/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

nvd-secondary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

Noroxi analysis

No Noroxi analysis for this record yet

We don't hand-write analysis for all 385,000+ vulnerabilities; that wouldn't be honest. For notable, high-impact vulnerabilities our team writes the mechanism, detection and remediation steps.

We use this product, ask for help

Change log

  1. Fix✗ → ✓

For records you follow, these changes also arrive as notifications. →

References

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records