Concrete CMS below 9.5.3 is missing authorization in the SEO Bulk Update Meta Tags editor
Key facts
- Attack vector
- Network
- Privileges required
- High
- User interaction
- None
- Attack complexity
- Low
- Attack requirements
- Present
- Impact type
- Security bypass
- Confidentiality · integrity · availability
- None · Low · None
- Fix status
- No fix listed
Attack profile from CVSS 4.0 · CNA. Fix status from CNA. Impact type from CWE-862.
Summary
In Concrete CMS before 9.5.3, the SEO Bulk Update Meta Tags editor did not check per-page edit permissions before saving. The saveRecord() action validated the per-page CSRF token but never called canEditPageProperties() for the target page, so a user who was granted access to the bulk SEO tool and could view (but not edit) a given page was able to change that page's meta title, meta description, and URL handle outside their edit scope, tampering with the presentation and live URLs of otherwise protected content. The Concrete CMS security team gave this vulnerability a CVSS v4.0 score of 2.1 with vector CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N. Thanks Andrew Gonzalez for reporting.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
No affected products listed by the sources yet.
CPE configurations NVD · 1
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:concretecms:concrete_cms:*:*:*:*:*:*:*:* | before 9.5.3 | Vulnerable | Concrete CMS |
- cpe:2.3:a:concretecms:concrete_cms:*:*:*:*:*:*:*:* Versions before 9.5.3 Vulnerable ·Concrete CMS
Remediation
No fixed version listed by the sources yet.
Timeline
- 2026-10-02 Threatist record created from CVE-2026-81923
- 2026-10-03 Alias added: GHSA-4q84-hvmx-qpr3
References
More Concrete Cms vulnerabilities
- TI-2026-23602 ConcreteCMS v9.4.7 contains a Denial of Service (DoS) vulnerability in the File Manager… CVSS 3.1MEDIUM 6.5
- TI-2023-23992 A Cross Site Scripting (XSS) vulnerability in Concrete CMS from versions 9.2.0 to 9.2.2… CVSS 3.1MEDIUM 5.4
- TI-2023-26495 Concrete CMS before 8.5.13 and 9.x before 9.2.2 allows unauthorized access because… CVSS 3.1CRITICAL 9.8
- TI-2026-14907 Missing authorization in Concrete CMS CVSS 4.0HIGH 8.7
- TI-2022-06200 Cleartext transmission of sensitive information in https://github.com/concrete5/concrete5 CVSS 3.1CRITICAL 9.8
- TI-2021-17294 An issue was discovered in Concrete CMS through 8.5.5. CVSS 3.1CRITICAL 9.8
Sources
- CVE-2026-81923 · CVE Program
- CVE-2026-81923 · NVD
- FIRST EPSS
- GHSA-4q84-hvmx-qpr3 · GitHub Advisory Database · CC BY 4.0
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