Craft CMS Unauthenticated Privilege Escalation via Account Reclamation

Craft CMS from 5.0.0 before 5.11.2 contains a privilege escalation vulnerability that allows unauthenticated public registrants to reclaim deactivated non-admin accounts while retaining their direct permissions. Attackers can register using a deactivated account, set a new password, and inherit permissions stored in userpermissions_users, enabling privileged account takeover when email verification is disabled.

Casky was already ahead

This CVE exploits attack patterns that Casky's 224matched skills already investigate — long before this vulnerability was disclosed. Claude's reasoning model maps these techniques to MITRE ATT&CK, so practitioners who ran these skills have already seen the threat behaviour in their findings.

Analysis

Craft CMS versions 5.0.0 through 5.11.1 contain a critical privilege escalation flaw that permits unauthenticated attackers to reclaim deactivated user accounts and inherit their permissions without re-authentication. By exploiting the account registration mechanism, an attacker can register using a deactivated account's username, set a new password, and gain access to all permissions previously assigned to that account—particularly dangerous when targeting deactivated admin or privileged accounts. This vulnerability is especially severe in installations with disabled email verification, as it eliminates the final authentication barrier. Organizations running affected Craft CMS versions face immediate risk of unauthorized administrative access, data exfiltration, and lateral movement within their systems.

Casky's 224 mapped skills detect the attack patterns underlying this vulnerability by analyzing MITRE ATT&CK technique TA0004 (Privilege Escalation). Practitioners using Casky's Claude-powered analysis would identify suspicious indicators including: registration requests targeting known deactivated accounts, successful authentication immediately following account registration without email verification, permission grants inherited from inactive user profiles, and access patterns showing newly-registered users performing administrative actions. The platform's extended reasoning capabilities correlate these behavioral signals across authentication logs, user management tables, and permission assignments to surface the account takeover chain. Security teams would see findings highlighting improper privilege inheritance during registration, missing email verification controls, and the ability for unauthenticated users to claim inactive identities—enabling them to prioritize remediation and hunt for evidence of exploitation in their Craft CMS deployments.

Live Threat IntelligenceComing soon

Casky Risk Score

—

EPSS Probability

—

Shodan Exposure

—

GreyNoise Signal

—

Composite risk scoring from EPSS, CISA KEV, Shodan, and GreyNoise — 21 security APIs correlated into a single Casky Risk Score. Coming in Casky Pro. Join early access →

224 Casky skills cover this attack pattern

These skills use Claude AI's reasoning model to surface findings in the same attack categories as CVE-2026-124429.

abusing-dpapi-for-credential-access

red teaming · high

Run

abusing-shadow-credentials-for-privesc

red teaming · high

Run

Access with Stolen Session Cookie

identity access management · low

Run

MITRE ATT&CK Techniques

TA0004

Investigate the attack patterns behind CVE-2026-124429

Casky has 224 skills that investigate the attack patterns behind CVE-2026-124429. Run one and get CVSS-scored findings in 3 minutes.

Run the skill that detects this →

X Instagram LinkedIn