Is CVE-2026-10721 in the CISA KEV catalog?

No. CVE-2026-10721 is not currently on the CISA Known Exploited Vulnerabilities list.

What is the CVSS severity of CVE-2026-10721?

CVE-2026-10721 has a CVSS v4 base score of 8.4 (HIGH).

What is the EPSS score for CVE-2026-10721?

CVE-2026-10721 has an EPSS score of 0.14% (4th percentile), estimating the probability of exploitation in the next 30 days.

How do I fix or mitigate CVE-2026-10721?

No published fix for CVE-2026-10721 has been found yet. Check the linked vendor advisories for guidance as it becomes available.

CVE & CISA-KEV Catalog

CVE-2026-10721

HIGH

8.4

CVSS v4

NVD

Description

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.

CWE-502Deserialization of Untrusted Data

How to fix

No published remediation has been found for this vulnerability's affected products yet.

Mitigation guidance may be in the linked vendor advisories in the References section below.

CVSS v4 Vector

Exploitability

Attack VectorLocal

Attack ComplexityLow

Privileges RequiredHigh

User InteractionNone

Impact

CVSS:4.0/AV:L/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/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

Exploit Intelligence

0.14%probability of exploitation in 30 days

4thpercentile

Low risk: more likely to be exploited than 4% of all known CVEs.

References

Other references1

documentation.concretecms.org

Related Vulnerabilities

Other CWE-502 (Deserialization of Untrusted Data) vulnerabilities, ordered by exploit likelihood. View all

CVE	Severity	CVSS	EPSS	Exploited	Fix
CVE-2023-0669	High	7.2	100%	KEV + Ransom	Fix
CVE-2021-44228	Critical	10.0	100%	KEV + Ransom	Fix
CVE-2021-35464	Critical	9.8	100%	KEV + Ransom	Fix
CVE-2023-29300	Critical	9.8	100%	KEV + Ransom	-
CVE-2025-53770	Critical	9.8	100%	KEV + Ransom	Fix
CVE-2022-47986	Critical	9.8	100%	KEV + Ransom	-

Embed a live status badge for CVE-2026-10721

Markdown

[![CVE-2026-10721](https://tridentstack.com/cve/badge/CVE-2026-10721.svg)](https://tridentstack.com/cve/CVE-2026-10721)

HTML

<a href="https://tridentstack.com/cve/CVE-2026-10721"><img src="https://tridentstack.com/cve/badge/CVE-2026-10721.svg" alt="CVE-2026-10721"></a>

Find and fix vulnerabilities across your fleet

TridentStack Control continuously scans your Windows, macOS, and Linux fleet for known vulnerabilities, prioritizes them by severity and active exploitation, and patches them automatically.

Start free

This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2026-06-17.