What’s Vulnerable › Vulnerabilities

CVE-2026-33710: Chamilo LMS has Weak REST API Key Generation (Predictable)

• Severity: high (CVSS 7.5 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.3% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-04-10 · updated 2026-10-26
• Weakness: CWE-330

Description

Chamilo LMS is a learning management system. Prior to 1.11.38 and 2.0.0-RC.3, REST API keys are generated using md5(time() + (user_id * 5) - rand(10000, 10000)). The rand(10000, 10000) call always returns exactly 10000 (min == max), making the formula effectively md5(timestamp + user_id*5 - 10000). An attacker who knows a username and approximate key creation time can brute-force the API key. This vulnerability is fixed in 1.11.38 and 2.0.0-RC.3.

Affected products

• chamilo-lms: before 1.11.38; 2.0.0-alpha1, 2.0.0-alpha2, 2.0.0-alpha3, 2.0.0-alpha4, 2.0.0-alpha5, 2.0.0-beta1 (+4) — fixed in 1.11.38

How to fix

Upgrade to a fixed version: chamilo-lms 1.11.38. Check the vendor advisory for mitigations.

References

• https://github.com/chamilo/chamilo-lms/commit/4448701bb8ec557e94ef02d19c72cbe9c49c2d09
• https://github.com/chamilo/chamilo-lms/commit/e7400dd840586ae134b286d0a2374f3d269a9a9d
• https://github.com/chamilo/chamilo-lms/security/advisories/GHSA-rpmg-j327-mr39

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