CyberSecBulletin
CVE-2026-33702NVD status: Analyzed

chamilo-lms: Authorization Bypass Through User-Controlled Key

Published Updated By the CyberSecBulletin desk

CVE-2026-33702 is a high-severity authorization bypass through user-controlled key vulnerability in chamilo-lms from Chamilo, with a CVSS 3.1 base score of 7.1 out of 10. It can be exploited remotely over the network by an attacker with a low-privileged account, without any action from a user. Affected chamilo-lms versions: < 1.11.38; >= 2.0.0-alpha.1, < 2.0.0-RC.3. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.25% chance of exploitation within 30 days, which is low compared with other CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Check which version of chamilo-lms you run against the affected versions below, and install the vendor's latest release.
  2. Read the advisory on github.com for workarounds and exact fixed builds.

Affected products and versions

VendorProductAffected versionsFixed in
Chamilochamilo-lms< 1.11.38; >= 2.0.0-alpha.1, < 2.0.0-RC.3Not stated

Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Attack vector
NetworkCan be exploited remotely over a network, including the internet.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
Privileges required
LowA basic user account is enough.
User interaction
NoneNo action by a victim is required.
Scope
UnchangedImpact stays within the vulnerable component.
Confidentiality
NoneNo data is disclosed.
Integrity
HighData or code can be modified at will.
Availability
LowPerformance or availability is reduced.

Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:L. Scored by CNA (github.com).

Official description

Chamilo LMS is a learning management system. Prior to 1.11.38 and 2.0.0-RC.3, Chamilo LMS contains an Insecure Direct Object Reference (IDOR) vulnerability in the Learning Path progress saving endpoint. The file lp_ajax_save_item.php accepts a uid (user ID) parameter directly from $_REQUEST and uses it to load and modify another user's Learning Path progress — including score, status, completion, and time — without verifying that the requesting user matches the target user ID. Any authenticated user enrolled in a course can overwrite another user's Learning Path progress by simply changing the uid parameter in the request. This vulnerability is fixed in 1.11.38 and 2.0.0-RC.3.

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Authorization Bypass Through User-Controlled Key

The system's authorization functionality does not prevent one user from gaining access to another user's data or record by modifying the key value identifying the data.

How developers prevent this class of flaw

  • For each and every data access, ensure that the user has sufficient privilege to access the record that is being requested.
  • Make sure that the key that is used in the lookup of a specific user's record is not controllable externally by the user or that any tampering can be detected.
  • Use encryption in order to make it more difficult to guess other legitimate values of the key or associate a digital signature with the key so that the server can verify that there has been no tampering.

More Authorization Bypass Through User-Controlled Key vulnerabilities (CWE-639)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: poc, automatable: no, technical impact: partial).
  3. Record last changed materially (score, affected products, status or references).

References

Other vulnerabilities in chamilo-lms

All chamilo-lms vulnerabilities

Recent Authorization Bypass Through User-Controlled Key vulnerabilities

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