What is the CVSS score of EUVD-2026-21537?

EUVD-2026-21537 has a CVSS 3.1 base score of 8.8 (High). CVSS vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H. EPSS exploitation probability: 0.0%.

Which versions of PHP are affected by EUVD-2026-21537?

Chamilo LMS versions prior to 2.0.0-RC.3 contain a remote code execution vulnerability that allows authenticated low-privilege users to execute arbitrary PHP code and achieve full system compromise…. A patch is available.

How to fix or mitigate EUVD-2026-21537?

Within 24 hours: identify all Chamilo LMS instances in production and verify current versions against 2.0.0-RC.3. Within 7 days: upgrade all affected Chamilo installations to version 2.0.0-RC.3 or later; restrict access to the /platform-config/list endpoint via network controls pending upgrade. Within 30 days: conduct security audit of Chamilo configuration changes and database logs to detect unauthorized modifications; review low-privilege user access to Chamilo administrative functions and implement principle of least privilege.

PHP EUVD-2026-21537

| CVE-2026-33618 HIGH

Eval Injection (CWE-95)

2026-04-10 GitHub_M

RCE PHP Code Injection

8.8

CVSS 3.1 · GitHub Advisory

Severity by source

GitHub Advisory PRIMARY

8.8 HIGH

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

Primary rating from GitHub Advisory · only source for this CVE.

CVSS VectorGitHub Advisory

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

Attack Vector

Network

Attack Complexity

Low

Privileges Required

Low

User Interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

Lifecycle Timeline

Re-analysis Queued

Apr 17, 2026 - 22:07 vuln.today

cvss_changed

Analysis Updated

Apr 16, 2026 - 05:58 EUVD-patch-fix

executive_summary

Re-analysis Queued

Apr 16, 2026 - 05:29 backfill_euvd_patch

patch_released

Patch available

Apr 16, 2026 - 05:29 EUVD

2.0.0-RC.3

EUVD ID Assigned

Apr 10, 2026 - 18:45 euvd

EUVD-2026-21537

Analysis Generated

Apr 10, 2026 - 18:45 vuln.today

CVE Published

Apr 10, 2026 - 18:10 nvd

HIGH 8.8

DescriptionGitHub Advisory

Chamilo LMS is a learning management system. Prior to .0.0-RC.3, the PlatformConfigurationController::decodeSettingArray() method uses PHP's eval() to parse platform settings from the database. An attacker with admin access (obtainable via Advisory 1) can inject arbitrary PHP code into the settings, which is then executed when any user (including unauthenticated) requests /platform-config/list. This vulnerability is fixed in 2.0.0-RC.3.

AnalysisAI

Remote code execution in Chamilo LMS versions prior to 2.0.0-RC.3 allows authenticated attackers with administrative privileges to inject and execute arbitrary PHP code via platform configuration settings. The PlatformConfigurationController::decodeSettingArray() method unsafely uses eval() to parse database-stored settings, executing injected code when any user-including unauthenticated visitors-accesses the /platform-config/list endpoint. Exploitation requires low-privilege authentication (PR:L) but delivers full system compromise with high confidentiality, integrity, and availability impact. No public exploit identified at time of analysis.

Technical ContextAI

Root cause is unsafe deserialization via PHP eval() in settings parser (CWE-95). Admin-injected payloads persist in database platform_config table, triggering code execution during unauthenticated HTTP requests to configuration listing endpoint. Attack chain leverages privilege escalation referenced in related Advisory 1 to achieve initial admin access, then plants persistent PHP backdoor executable by anonymous users.

RemediationAI

Vendor-released patch: upgrade immediately to Chamilo LMS 2.0.0-RC.3 or later, which removes eval() usage from PlatformConfigurationController::decodeSettingArray(). The fix commit replaces unsafe deserialization with secure parsing methods (https://github.com/chamilo/chamilo-lms/commit/f2c382c94a3f153a4d7e5ce5686c5a219fd09b3b). Organizations unable to upgrade should restrict administrative account access, audit existing platform settings for injected code, implement Web Application Firewall rules blocking /platform-config/list for unauthenticated users, and monitor server logs for anomalous eval() execution patterns. Full advisory available at https://github.com/chamilo/chamilo-lms/security/advisories/GHSA-hp4w-jmwc-pg7w. No workaround fully mitigates risk without patching.