Concrete CMS version 9 below 9.3.3 and below 8.5.18 are vulnerable to Stored XSS in RSS Displayer
Noroxi assessment
Priority: Monitor (action score 20/100)
- The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
- Probability of exploitation in the next 30 days: 0.49% (FIRST EPSS).
- Anyone who can reach it over the internet can trigger it. Administrator privileges are required. No user action is required. No special conditions are required; it is repeatable.
- Fixed version: Concrete CMS Concrete CMS 8.5.18, 9.3.3.
Low priority for now. Upgrade to Concrete CMS Concrete CMS 8.5.18, 9.3.3 or later.
Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it
Primary sources: NVD · CVE.org · FIRST EPSS
Concrete CMS versions 9.0.0 to 9.3.2 and below 8.5.18 are vulnerable to Stored XSS in RSS Displayer when user input is stored and later embedded into responses. A rogue administrator could inject malicious code into fields due to insufficient input validation. The Concrete CMS security team gave this vulnerability a CVSS v4 score of 5.1 with vector https://www.first.org/cvss/calculator/4.0#CVSS:4.0/AV:N/AC:H/AT:N/PR:H/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N Thanks, m3dium for reporting. (CNA updated this risk rank on 17 Jan 2025 by lowering the AC based on CVSS 4.0 documentation that access privileges should not be considered for AC)
- Published
- Aug 12, 2024
- Updated
- Jun 17, 2026
- EPSS
- 0.4% · 41th percentile
- CWE
- CWE-79
Report tools
Action score
20
Monitor
Low priority for now.
- CVSS
- 20 / 40 · 5.1 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 0 / 30 · 0.4%
CISA SSVC decision
- Exploitation
- none
- Automatable
- no
- Technical impact
- partial
Vulnrichment: CISA's decision-tree inputs.
CNA vs NVD score
- NVD
- —
- CNA · ConcreteCMS
- 5.1
- 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:N/VC:L/VI:N/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.
Get told when this record changes
- Not in KEV: no record of exploitation in the wild
- No public exploit code on record
- A fix has been released
If any of these changes, we'll tell you in the daily email digest.
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Noroxi analysis
What does it mean in your environment?
The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.
We use this product, ask for helpAffected systems
Is your version affected?
Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.
| Vendor | Product | CPE |
|---|---|---|
| concretecms | concrete cms | cpe:2.3:a:concretecms:concrete_cms |
Limit the impact of XSS
This is a cross-site scripting (XSS) vulnerability. A well-configured Content-Security-Policy doesn't fix it, but greatly reduces its impact. Check your site's CSP and other security headers for free.
Check security headersAffected versions
NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.
- concretecms concrete cmsbefore 8.5.18
- concretecms concrete cms9.0.0 and later · before 9.3.3
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 9.3.3affected · git
- 5.0.0 and later · before 8.5.18affected · git
Package-level exposure
OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.
| Ecosystem | Package | Affected range | Fix |
|---|---|---|---|
| Packagist | concrete5/concrete5 | from 9.0.0RC1 · before 9.3.3 | 9.3.3 |
| Packagist | concrete5/concrete5 | before 8.5.18 | 8.5.18 |
Same product
concretecms: all recordsOther highest-scoring records for the same primary product.
- CVE-2026-6826Concrete 9.5.0 and below has file usage disclosure via missing permission check in Usage controller60This week
- 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 c40Plan
- 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
Published before and after this one in the same product
- ← EarlierCVE-2024-4353Aug 1, 2024 · Stored XSS in Generate Board Name Input Field18Monitor
- ← EarlierCVE-2024-7394Aug 8, 2024 · Concrete CMS version 9.0.0 through 9.3.2 and below 8.5.18 - Stored XSS in getAttributeSetName()18Monitor
- Later →CVE-2024-7512Aug 12, 2024 · Concrete CMS Stored XSS in Board instances18Monitor
Remediation
Which version to upgrade to
Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.
| Product / package | Fixed version | Source |
|---|---|---|
| Concrete CMS Concrete CMS | 8.5.18 | Vendor (CNA) |
| Concrete CMS Concrete CMS | 9.3.3 | Vendor (CNA) |
| Packagist:concrete5/concrete5 | 8.5.18 | Package registry (OSV) |
| Packagist:concrete5/concrete5 | 9.3.3 | Package registry (OSV) |
Exploit status
No known public exploit
No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.
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.
No dated events beyond publication.
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.
Credits
All researchersFinders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.
- m3diumreporter
Variant candidates
Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.
- CVE-2023-28475472 days apartConcrete CMS (previously concrete5) versions 8.5.12 and below, and versions 9.0 through 9.1.3 is vulnerable to Reflected XSS on the Reply fo24Monitor
- CVE-2023-48649269 days apartConcrete CMS before 8.5.13 and 9.x before 9.2.2 allows stored XSS on the Admin page via an uploaded file name.21Monitor
- CVE-2023-44761311 days apartMultiple Cross Site Scripting (XSS) vulnerabilities in Concrete CMS versions affected to 8.5.13 and below, and 9.0.0 through 9.2.1 allow a l21Monitor
- CVE-2023-44762311 days apartA Cross Site Scripting (XSS) vulnerability in Concrete CMS from versions 9.2.0 to 9.2.2 allows an attacker to execute arbitrary code via a c21Monitor
- CVE-2023-44764311 days apartA Cross Site Scripting (XSS) vulnerability in Concrete CMS before 9.2.3 exists via the Name parameter during installation (aka Site of Insta21Monitor
- CVE-2023-44765311 days apartA Cross Site Scripting (XSS) vulnerability in Concrete CMS versions 8.5.12 and below, and 9.0 through 9.2.1 allows an attacker to execute ar21Monitor
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 user action is 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
- None
- Scope
- X
Weakness class (CWE)
CWE-79 · Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')CVSS vector
CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:L/VI:N/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
Root cause
User content is inserted into the page as HTML. The browser interprets the content as code rather than data.
The bug in code
The whole CWE-79 classA representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.
Vulnerable
commentEl.innerHTML = comment.body;Fixed
commentEl.textContent = comment.body;Attack context
MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.
Attack patterns (CAPEC)
ATT&CK techniques
—
Change log
- Fix✗ → ✓
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References
Show all references (3 more)Show less
Vendor advisories and official records. Exploit/PoC links are deliberately left out.