VulnerabilityPublished 14 Apr 2026

CVE-2026-34602: chamilo-lms · Insecure Direct Object Reference

Affects chamilo-lmsSource CVE Database V5

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Not known to be exploited · CVSS 7.1 High : upgrade to 2.0.0-RC.3 soon.

Data as of 29 Oct 2026, 19:04 UTC

CVSS 3.1 base score

7.1High

How severe the flaw is on the 0–10 CVSS scale.

EPSS: 0.2% chance of exploitation in 30 days – higher than 10% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 2.0.0-RC.3

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

Attack Vector: Network
Attack Complexity: Low
Privileges Required: Low
User Interaction: None
Scope: Unchanged
Confidentiality: Low
Integrity: High
Availability: None

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed, up to and including the entire Internet. Such a vulnerability is often termed 'remotely exploitable' and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: Low: The attacker is authorized with (i.e., requires) privileges that provide basic user capabilities that could normally affect only settings and files owned by a user. Alternatively, an attacker with Low privileges may have the ability to cause an impact only to non-sensitive resources.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
Confidentiality: Low: There is some loss of confidentiality. Access to some restricted information is obtained, but the attacker does not have control over what information is obtained, or the amount or kind of loss is limited. The information disclosure does not cause a direct, serious loss to the impacted component.
Integrity: High: There is a total loss of integrity, or a complete loss of protection. For example, the attacker is able to modify any/all files protected by the impacted component. Alternatively, only some files can be modified, but malicious modification would present a direct, serious consequence to the impacted component.
Availability: None: There is no impact to availability within the impacted component.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 14 Apr 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 29 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponized: A Metasploit exploit module or Exploit-DB entry exists (Metasploit scanner modules do not count), or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Upgrade chamilo-lms to 2.0.0-RC.3.

Affected software

Product	Affected	Fixed in
chamilochamilo-lms	Affected <2.0.0-RC.3	Fixed in 2.0.0-RC.3
GitHubchamilo/chamilo-lms`pkg:github/chamilo/chamilo-lms`Other threats	Affected =2.0.0-RC.3	Fixed in–

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

This vulnerability is fixed in Chamilo LMS version 2.0.0-RC.3. Users should upgrade to this version or later to remediate the issue. Since this is not a cloud service, patching the affected software is required to mitigate the risk. Patch status is confirmed by the vendor advisory stating the fix is included in version 2.0.0-RC.3.

Description

Chamilo LMS versions prior to 2.0.0-RC.3 contain an authorization bypass vulnerability in the /api/course_rel_users endpoint. An authenticated attacker can manipulate the user parameter to enroll arbitrary users into courses without proper authorization. This occurs because the backend does not verify ownership or permission for the user ID supplied. The vulnerability allows unauthorized access to course materials and compromises enrollment controls. The issue is fixed in version 2.0.0-RC.

Impact

Exploitation of this vulnerability allows an authenticated attacker to enroll arbitrary users into courses without authorization, potentially granting unauthorized access to course materials and compromising the integrity of enrollment controls within the Chamilo LMS platform. The confidentiality and integrity of course enrollment data can be impacted. There is no indication of availability impact. No known exploits in the wild have been reported.

Summary

CVE-2026-34602 is an authorization bypass vulnerability (CWE-639) in Chamilo LMS before version 2.0.0-RC.3. The /api/course_rel_users API endpoint improperly trusts user-supplied input for the user field, lacking server-side verification that the requester is authorized to act on behalf of the specified user ID. This insecure direct object reference (IDOR) flaw allows an authenticated attacker to enroll any arbitrary user into any course, bypassing enrollment restrictions and potentially exposing course content to unauthorized users. The vulnerability has been addressed in Chamilo LMS version 2.0.0-RC.3.

CWE-639Authorization Bypass Through User-Controlled Key (opens in a new tab)
Base weaknessLikelihood of exploit: HighCWE Top 25 (2025): #24OWASP Top 10 A01:2025: Broken Access Control (opens in a new tab)
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.
Architecture and Design
For each and every data access, ensure that the user has sufficient privilege to access the record that is being requested.
Architecture and Design · Implementation
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.
Architecture and Design
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.
OWASP Cheat Sheets
Access Control (opens in a new tab)
Authorization Testing Automation (opens in a new tab)
Cross-Site Request Forgery Prevention (opens in a new tab)
Insecure Direct Object Reference Prevention (opens in a new tab)
Authorization (opens in a new tab)
OWASP ASVS 4.0.3
V4.1.2 (opens in a new tab)
V4.2.1 (opens in a new tab)
V8.3.8 (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 22 Apr 2026, 06:50 UTC

WeaknessesCWE-639

Technical details

References

Community reviews

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