Which versions of Pagekit CMS are affected by CVE-2026-57518?

Pagekit CMS 1.0.18 contains a privilege escalation vulnerability (CVE-2026-57518, CVSS 8.7) enabling remote code execution and full server compromise.

Is there a public PoC exploit available for CVE-2026-57518?

Yes, a public proof-of-concept exploit is available for CVE-2026-57518. Prioritise patching immediately. EPSS: 0.5%.

How to fix or mitigate CVE-2026-57518?

24 HOURS: Restrict administrative access to Pagekit 1.0.18 admin consoles; audit all administrative accounts and their permissions; disable package management features if operationally feasible; review access logs for suspicious activity. 7 DAYS: Complete inventory of all Pagekit 1.0.18 installations; implement network segmentation and access controls (IP whitelisting, multi-factor authentication) on admin interfaces; revoke unnecessary elevated permissions from administrative accounts. 30 DAYS: Monitor Pagekit security advisories for vendor patch release; evaluate CMS platform alternatives; deploy web application firewall rules to detect exploitation patterns.

Pagekit CMS CVE-2026-57518

Q: What is the CVSS score of CVE-2026-57518?

CVE-2026-57518 has a CVSS 4.0 base score of 8.7 (High). CVSS vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/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. EPSS exploitation probability: 0.5%.

EUVD-2026-39795 HIGH

Missing Authorization (CWE-862)

2026-06-26 VulnCheck

GHSA-rc6m-346q-rgq6

PHP Authentication Bypass Privilege Escalation RCE Pagekit

8.7

CVSS 4.0 · Vendor: VulnCheck

Severity by source

Vendor (VulnCheck) PRIMARY

8.7 HIGH

CVSS:4.0/AV:N/AC:L/AT:N/PR:L/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

vuln.today AI

9.9 CRITICAL

Network endpoint with low-privileged authenticated account (PR:L) and no interaction; authorization bypass crosses a privilege boundary to RCE (S:C) with full C/I/A impact.

3.1 AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H

4.0 AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

Primary rating from Vendor (VulnCheck).

CVSS VectorVendor: VulnCheck

Attack Vector

Network

Attack Complexity

Low

Privileges Required

Low

User Interaction

None

Scope

Lifecycle Timeline

Analysis Generated

Jun 26, 2026 - 17:21 vuln.today

DescriptionCVE.org

Pagekit CMS 1.0.18 contains a privilege escalation vulnerability that allows authenticated users with the 'user: manage users' permission to escalate privileges by assigning arbitrary custom roles to themselves due to missing authorization checks in UserApiController::saveAction(). Attackers can assign themselves a custom role with the 'system: manage packages' permission and then upload and install a malicious PHP package through the admin package installer to achieve remote code execution.

Articles & Coverage 1

News 8 New PHP Vulnerabilities - 2 Critical, 6 High, 1 With POC Jun 27, 2026

AnalysisAI

Privilege escalation to remote code execution in Pagekit CMS 1.0.18 lets an authenticated user holding the 'user: manage users' permission grant themselves arbitrary custom roles via an unprotected UserApiController::saveAction(), then assign a role carrying 'system: manage packages' to upload a malicious PHP package through the admin installer and run arbitrary code. Publicly available exploit code exists (gist by sermikr0, reported by VulnCheck), and the chain converts a limited management permission into full server compromise. No public evidence of active exploitation has been confirmed (not in CISA KEV).

Technical ContextAI

Pagekit is a PHP-based, modular open-source CMS built on a marketplace/package extension model where packages are PHP code installed through an admin 'package installer'. The root cause is CWE-862 (Missing Authorization): the saveAction() endpoint in UserApiController does not verify that the caller is permitted to assign the roles contained in the request, so a user with only the 'user: manage users' capability can attach any custom role - including privileged ones - to their own account. Because role-to-permission binding gates the 'system: manage packages' capability, and that capability allows installing arbitrary PHP packages, the authorization gap collapses the boundary between user administration and code execution. The single affected CPE is cpe:2.3:a:pagekit:pagekit:*:*:*:*:*:*:*:*.

RemediationAI

No vendor-released patch version was identified at time of analysis, so apply compensating controls. As the primary mitigation, restrict assignment of the 'user: manage users' permission to fully trusted administrators only, since this is the prerequisite capability the attack abuses; review existing custom roles and remove 'user: manage users' from any non-administrator role. Additionally, limit or disable the admin package installer ('system: manage packages') and restrict who can reach the admin API, recognizing the trade-off that this blocks legitimate extension installation and must be re-enabled manually for maintenance. Monitor user role-assignment changes and package-installation events for anomalous self-elevation. Consult the VulnCheck advisory at https://www.vulncheck.com/advisories/pagekit-cms-privilege-escalation-via-userapicontroller for details, and upgrade to a fixed release once the vendor publishes one. Do not deploy version 1.0.18 in multi-user configurations until remediated.