VulnerabilityPublished 16 Mar 2026

CVE-2026-30876: chamilo-lms · Observable Response Discrepancy

Affects chamilo-lmsSource CVE Database V5

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Not known to be exploited · CVSS 6.3 Medium : upgrade to 1.11.36 when convenient.

Data as of 29 Oct 2026, 19:04 UTC

CVSS 4.0 base score

6.3Medium

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

EPSS: 0.2% chance of exploitation in 30 days – higher than 11% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 1.11.36

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

Attack Vector: Network
Attack Complexity: Low
Attack Requirements: Present
Privileges Required: None
User Interaction: None
Vulnerable system confidentiality: Low
Vulnerable system integrity: None
Vulnerable system availability: None
Subsequent system confidentiality: None
Subsequent system integrity: None
Subsequent system availability: None

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

Attack Vector: Network: The vulnerable system is bound to the network stack and the set of possible attackers extends beyond the other options listed below, 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: The attacker must take no measurable action to exploit the vulnerability. The attack requires no target-specific circumvention to exploit the vulnerability. An attacker can expect repeatable success against the vulnerable system.
Attack Requirements: Present: The successful attack depends on the presence of specific deployment and execution conditions of the vulnerable system that enable the attack. These include: a race condition must be won to successfully exploit the vulnerability (the successfulness of the attack is conditioned on execution conditions that are not under full control of the attacker, or the attack may need to be launched multiple times against a single target before being successful); the attacker must inject themselves into the logical network path between the target and the resource requested by the victim (e.g. vulnerabilities requiring an on-path attacker).
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files of the vulnerable system to carry out an attack.
User Interaction: None: The vulnerable system can be exploited without interaction from any human user, other than the attacker.
Vulnerable system 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 Vulnerable System.
Vulnerable system integrity: None: There is no loss of integrity within the Vulnerable System.
Vulnerable system availability: None: There is no impact to availability within the Vulnerable System.
Subsequent system confidentiality: None: There is no loss of confidentiality within the Subsequent System or all confidentiality impact is constrained to the Vulnerable System.
Subsequent system integrity: None: There is no loss of integrity within the Subsequent System or all integrity impact is constrained to the Vulnerable System.
Subsequent system availability: None: There is no impact to availability within the Subsequent System or all availability impact is constrained to the Vulnerable System.

Definitions: FIRST CVSS v4.0 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 16 Mar 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 and chamilo/chamilo-lms to 1.11.36.

Affected software

Product	Affected	Fixed in
chamilochamilo-lms	Affected <1.11.36	Fixed in 1.11.36
GitHubchamilo/chamilo-lms`pkg:github/chamilo/chamilo-lms`Other threats	Affected <1.11.36	Fixed in 1.11.36

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

AI-suggested

To mitigate CVE-2026-30876, organizations should immediately upgrade Chamilo LMS to version 1.11.36 or later, where the vulnerability is patched. If immediate upgrade is not feasible, administrators should implement application-layer mitigations such as uniform error messages and response times for authentication failures to obfuscate valid usernames. Rate limiting and IP-based throttling on login and user validation endpoints can reduce the effectiveness of enumeration attempts. Deploying Web Application Firewalls (WAFs) with rules to detect and block suspicious enumeration patterns can provide additional protection. Monitoring authentication logs for repeated failed attempts and unusual access patterns can help detect ongoing enumeration attacks. Educating users about phishing risks and enforcing strong password policies, including multi-factor authentication where possible, will reduce the impact of compromised credentials obtained through enumeration-facilitated attacks.

Description

Chamilo LMS is a learning management system. Prior to version 1.11.36, Chamilo is vulnerable to user enumeration with valid/invalid username. This issue has been patched in version 1.11.36.

Impact

The primary impact of CVE-2026-30876 is information disclosure through user enumeration, which can significantly aid attackers in identifying valid user accounts within an organization’s Chamilo LMS deployment. This can lead to increased risk of targeted phishing campaigns, credential stuffing attacks, and brute force password attempts against confirmed usernames. While the vulnerability does not allow direct unauthorized access or data manipulation, the enumeration capability lowers the attacker's effort and increases the likelihood of successful subsequent attacks. For educational institutions and organizations relying on Chamilo LMS for sensitive or personal data, this can result in compromised user accounts, privacy violations, and potential reputational damage. Additionally, automated scanning tools could exploit this vulnerability at scale, increasing the attack surface. The lack of required authentication or user interaction means attackers can perform enumeration remotely and stealthily, increasing risk especially in internet-facing LMS deployments.

CWE-204Observable Response Discrepancy (opens in a new tab)
Base weakness
The product provides different responses to incoming requests in a way that reveals internal state information to an unauthorized actor outside of the intended control sphere.
Architecture and Design · Separation of Privilege
Compartmentalize the system to have "safe" areas where trust boundaries can be unambiguously drawn. Do not allow sensitive data to go outside of the trust boundary and always be careful when interfacing with a compartment outside of the safe area.
Implementation
Ensure that error messages only contain minimal details that are useful to the intended audience and no one else. The messages need to strike the balance between being too cryptic (which can confuse users) or being too detailed (which may reveal more than intended).
OWASP Cheat Sheets
Error Handling (opens in a new tab)
Logging (opens in a new tab)
OWASP ASVS 4.0.3
V8.3.4 (opens in a new tab)
V14.3.3 (opens in a new tab)
V7.3.3 (opens in a new tab)
Attack patterns
ICMP IP Total Length Field Probe (opens in a new tab)
ICMP IP 'ID' Field Error Message Probe (opens in a new tab)
Application Fingerprinting (opens in a new tab)
System Footprinting (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 16 Mar 2026, 19:44 UTC

WeaknessesCWE-204

Technical details

References

Community reviews

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