NVD / CVE Program· CNA hackerone

CVE-2021-22966: Privilege escalation from Editor to Admin using Groups in Concrete CMS versions 8.5.6 and below.

Noroxi assessment

Priority: Monitor (action score 35/100)

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: 0.98% (FIRST EPSS); higher than 62.4% of all records.
Anyone who can reach it over the internet can trigger it. A low-privileged account is enough. No user action is required. No special conditions are required; it is repeatable.
Fixed version: concrete5/core (Packagist) 8.5.7.

Low priority for now. Upgrade to concrete5/core (Packagist) 8.5.7 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

Privilege escalation from Editor to Admin using Groups in Concrete CMS versions 8.5.6 and below. If a group is granted "view" permissions on the bulkupdate page, then users in that group can escalate to being an administrator with a specially crafted curl. Fixed by adding a check for group permissions before allowing a group to be moved. Concrete CMS Security team CVSS scoring: 7.1 AV:N/AC:H/PR:L/UI:R/S:U/C:H/I:H/A:HCredit for discovery: "Adrian Tiron from FORTBRIDGE ( https://www.fortbridge.co.uk/ )"This fix is also in Concrete version 9.0.0

HighCVSS 8.8 · v3.1—No exploit Fix available

Broken access control (IDOR)

GHSA-j4mv-2rv7-v2j9

Published: Nov 19, 2021
Updated: Jun 16, 2026
EPSS: 0.9% · 62th percentile
CWE: CWE-863

Report tools

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Action score

Monitor

Low priority for now.

CVSS: 35 / 40 · 8.8 / 10
CISA KEV: 0 / 30 · Not listed
EPSS: 0 / 30 · 0.9%

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No public exploit code on record
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Noroxi analysis

What does it mean in your environment?

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Affected 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

Affected versions

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

concretecms concrete cmsbefore 8.5.7

Versions reported by the vendor

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

n/a https://github.com/concrete5/concrete5
- Fixed in version 9 and in version 8.5.7affected

Package-level exposure

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

Ecosystem	Package	Affected range	Fix
Packagist	concrete5/core	before 8.5.7	8.5.7

Same product

concretecms: all records

Other 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 controller
60This 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 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

Published before and after this one in the same product

← EarlierCVE-2021-22958Oct 7, 2021 · A Server-Side Request Forgery vulnerability was found in concrete5 < 8.5.5 that allowed a decimal notation encoded IP address to bypass the
39Monitor
← EarlierCVE-2021-22951Nov 19, 2021 · Unauthorized individuals could view password protected files using view_inline in Concrete CMS (previously concrete 5) prior to version 8.5.
30Monitor
Later →CVE-2021-22967Nov 19, 2021 · In Concrete CMS (formerly concrete 5) below 8.5.7, IDOR Allows Unauthenticated User to Access Restricted Files If Allowed to Add Message to
30Monitor

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
Packagist:concrete5/core	8.5.7	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.

No history yet (it accumulates with the daily EPSS job).

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.

No credits in the CNA record.

Variant candidates

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

No nightly-computed relations.

Chain candidates

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

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Bug bounty scope