Cyber Resilience

CVE-2026-8327

Concretecms Concrete Cms ≤ 9.5.1

Published
21 May 2026
Modified
23 July 2026
CVSS Score v4 5.3
Click a component to see what it means
Raw vectorCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:L/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
EPSS Score 0.0018 8th percentile
Risk Priority 31 floored blend · peak EPSS

Summary

CVE-2026-8327 is a medium-severity Improper Privilege Management (CWE-269) vulnerability in Concretecms Concrete Cms. Its CVSS base score is 5.3 (Medium).

Operationally, exploitation aligns with the MITRE ATT&CK technique Abuse Elevation Control Mechanism (T1548); ranked at the 8th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified map to AC-2 (Account Management) and AC-24 (Access Control Decisions) — see the control section below for these in your framework.

OWASP Top 10 for Web (2025)

EU & UK References

Vulnerability Data

Concrete CMS below 9.5.0 and below is vulnerable to password change without reauthorization and session-hardening bypass. The user-profile edit controller passes the entire raw POST array to UserInfo::update() without field whitelisting resulting in password change without requiring the current password…

more

and also resulting in registered users able to disable the per-user-IP-pinning in the session validator which is meant to detect hijacking. The Concrete CMS security team gave this vulnerability a CVSS v.4.0 score of 5.3 with vector CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N. Thanks 0x4c616e for reporting.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise Techniques

T1548 Abuse Elevation Control Mechanism Privilege Escalation
Adversaries may circumvent mechanisms designed to control privilege elevation to gain higher-level permissions.
T1098 Account Manipulation Persistence
Adversaries may manipulate accounts to maintain and/or elevate access to victim systems.
T1098.001 Additional Cloud Credentials Persistence
Adversaries may add adversary-controlled credentials to a cloud account to maintain persistent access to victim accounts and instances within the environment.
T1134 Access Token Manipulation Stealth
Adversaries may modify access tokens to operate under a different user or system security context to perform actions and bypass access controls.
T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
T1548.001 Setuid and Setgid Privilege Escalation
An adversary may abuse configurations where an application has the setuid or setgid bits set in order to get code running in a different (and possibly more privileged) user’s context.
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2026-8239Same product: Concretecms Concrete Cms
CVE-2026-8238Same product: Concretecms Concrete Cms
CVE-2026-7879Same product: Concretecms Concrete Cms
CVE-2026-8237Same product: Concretecms Concrete Cms
CVE-2026-8236Same product: Concretecms Concrete Cms
CVE-2026-8350Same product: Concretecms Concrete Cms
CVE-2023-28473Same product: Concretecms Concrete Cms
CVE-2026-8240Same product: Concretecms Concrete Cms
CVE-2026-7887Same product: Concretecms Concrete Cms
CVE-2025-8573Same product: Concretecms Concrete Cms

Affected Assets

concretecms
concrete cms
≤ 9.5.1

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

Detect
Catch it (NIST detect / respond)

Harden
Shrink the surface (DISA STIG)
  • 5 hardening rules · 5 OS baselines
Validate
Prove the fix (OWASP ASVS)

Mitigating Controls (NIST 800-53 r5) AI

Account management directly governs assignment and tracking of privileges so proper implementation stops the weakness from being introduced.

Requiring explicit access-control decisions ensures privileges are evaluated rather than assumed or omitted.

Access enforcement applies the correct privilege checks at every request, structurally preventing unintended spheres of control.

Separation of duties constrains how privileges may be assigned, reducing the chance of overly broad actor control.

Least privilege is the direct countermeasure to improper privilege management; implementing it eliminates the root cause.

Re-authentication explicitly requires users to prove identity before performing sensitive actions such as password changes.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.AA-01 mostly match
prevents

Credential management practices directly enforce re-authentication for password changes.

PR.AA-03 mostly match
prevents

Authentication requirements include verifying identity before allowing credential modifications.

PR.AA-05 mostly match
prevents

PR.AA-05 enforces least privilege/SoD and periodic reviews that directly remove most privilege-assignment defects, yet CWE-269 also covers escalation paths and role design outside a single access-management control.

PR.PS-06 mostly match
prevents

Secure SDLC practices directly require allow-listing of mutable object attributes and input validation to block mass-assignment flaws.

PR.PS-01 partial match
prevents

Config baselines and default reviews can enforce some privilege-related settings (one facet) but do not address code-level assignment/tracking logic that defines CWE-269.

PR.PS-05 partial match
prevents

PR.PS-05 can partially limit exploitability of some privilege issues via execution restrictions, but does not address the core design/implementation flaws of CWE-269 at all.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

prevents

Requiring owner approval, segregation of duties, and periodic reviews prevents the assignment of excessive or unnecessary privileges to users or processes.

prevents

Enforcing minimum-necessary privileges, temporary grants, and separation of administrative versus normal identities prevents the over-assignment of rights that CWE-269 describes.

prevents

Secure coding standards explicitly forbid unsafe dynamic attribute assignment and require property allow-lists.

finds

Security testing can detect mass-assignment flaws but does not itself prevent them at runtime.

prevents

Dynamic techniques that grant the minimum necessary rights for a given time window and revoke them afterward reduce the window in which excessive or unnecessary privileges can be exploited.

prevents

Explicit restrictions on privileged access and segregation of duties limit the scope of privileges that can be assigned, reducing the chance that excessive or unnecessary privileges are granted to entities.

Hardening callouts derived

Configuration rules from DISA STIG baselines that bear on weaknesses of the type cited by this CVE. Each rule is shown with the relationship its mapping actually records, against the CWE it was authored against. Derived via CVE→CWE over `controls_xwalks` (authoritative rows only; rows rated `none` are excluded).

Windows 10 (1 rule)
  • V-220712 Only accounts responsible for the administration of a system must have Administrator rights on the system. prevents CWE-269
Windows 11 (1 rule)
  • V-253269 Only accounts responsible for the administration of a system must have Administrator rights on the system. prevents CWE-269
Windows Server 2016 (1 rule)
  • V-225007 Only administrators responsible for the member server or standalone or nondomain-joined system must have Administrator rights on the system. prevents CWE-269
Windows Server 2019 (1 rule)
  • V-205746 Windows Server 2019 must only allow Administrators responsible for the member server or standalone or nondomain-joined system to have Administrator rights on the system. prevents CWE-269
Windows Server 2022 (1 rule)
  • V-254428 Windows Server 2022 must only allow administrators responsible for the member server or standalone or nondomain-joined system to have Administrator rights on the system. prevents CWE-269

References