Deserialization of untrusted data in Concrete CMS
Priority LOW 37CWE-502Published · Updated
Key facts
- Attack vector
- Local
- Privileges required
- High
- User interaction
- None
- Attack complexity
- Low
- Attack requirements
- None
- Impact type
- Code execution
- Confidentiality · integrity · availability
- High · High · High
- Fix status
- Fixed
Attack profile from CVSS 4.0 · CNA. Fix status from CNA and GitHub. Impact type from CWE-502.
Summary
Concrete CMS below 9.5.2 is vulnerable to PHP Object Injection via unserialize() calls in the in Permission, Cache, and Search components. An unauthenticated attacker may trigger arbitrary PHP object instantiation if a malicious serialized payload has been placed in the database. Thanks XananasX7 for reporting.
Why it matters now
Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00146 3rd percentileScored 2026-11-07
Fix Fixed concrete5/concrete5 (Packagist): 9.5.2
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Total
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| — | concrete5/concrete5 (Packagist) | before 9.5.2 | 9.5.2 | Patch available | GHSA-g82f-9pw7-773w |
- concrete5/concrete5 (Packagist) Vendor— Affected before 9.5.2 Fixed in 9.5.2 Patch available GHSA-g82f-9pw7-773w
CPE names Threatist (inferred) · 1
Inferred from how NVD named this product before; not given by a source.
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:concretecms:concrete_cms:*:*:*:*:*:*:*:* | — | — | Concrete CMS |
- cpe:2.3:a:concretecms:concrete_cms:*:*:*:*:*:*:*:* Versions — — ·Concrete CMS
Remediation
- Fix · GHSA-g82f-9pw7-773w concrete5/concrete5 (Packagist) Fixed in 9.5.2 Advisory →
Timeline
- 2026-10-02 Threatist record created from CVE-2026-10721
- 2026-10-03 Alias added: GHSA-g82f-9pw7-773w
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-2026-10721 · CVE Program
- CVE-2026-10721 · NVD
- FIRST EPSS
- GHSA-g82f-9pw7-773w · GitHub Advisory Database · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences