VulnerabilityPublished 2 Mar 2026

CVE-2025-52564: chamilo-lms · Basic XSS

Affects chamilo-lmsSource CVE Database V5

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Not known to be exploited · CVSS 6.9 Medium : upgrade to 1.11.30 when convenient.

Data as of 30 Oct 2026, 11:52 UTC

CVSS 4.0 base score

6.9Medium

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

EPSS: 0.2% chance of exploitation in 30 days – higher than 13% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 1.11.30

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

Attack Vector: Network
Attack Complexity: Low
Attack Requirements: None
Privileges Required: None
User Interaction: None
Vulnerable system confidentiality: None
Vulnerable system integrity: Low
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: None: The successful attack does not depend on the deployment and execution conditions of the vulnerable system. The attacker can expect to be able to reach the vulnerability and execute the exploit under all or most instances of the vulnerability.
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: None: There is no loss of confidentiality within the Vulnerable System.
Vulnerable system integrity: Low: Modification of data is possible, but the attacker does not have control over the consequence of a modification, or the amount of modification is limited. The data modification does not have a direct, serious impact to 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 2 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 30 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 1.11.30.

Affected software

Product	Affected	Fixed in
chamilochamilo-lms	Affected <1.11.30	Fixed in 1.11.30
GitHubchamilo/chamilo-lms`pkg:github/chamilo/chamilo-lms`Other threats	Affected <1.11.30	Fixed in 1.11.30

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-2025-52564, organizations should immediately upgrade Chamilo LMS installations to version 1.11.30 or later, where the vulnerability has been patched. If immediate upgrade is not feasible, administrators should implement web application firewall (WAF) rules to detect and block suspicious requests containing malicious payloads in the 'open' parameter of help.php. Input validation and output encoding should be enforced at the application level to sanitize user-supplied data rigorously. Additionally, enabling Content Security Policy (CSP) headers can help restrict the execution of unauthorized scripts in users' browsers, reducing the impact of potential XSS attacks. Regular security audits and penetration testing of the LMS environment should be conducted to identify and remediate similar vulnerabilities proactively. User education on recognizing phishing attempts and suspicious links can also reduce the likelihood of successful exploitation. Finally, monitoring web server logs for unusual access patterns to help.php with suspicious parameters can provide early detection of exploitation attempts.

Description

Chamilo is a learning management system. Prior to version 1.11.30, the open parameter of help.php fails to properly sanitize user input. This allows an attacker to inject arbitrary HTML, such as underlined text, via a crafted URL. This issue has been patched in version 1.11.30.

Impact

The impact of CVE-2025-52564 on organizations using Chamilo LMS can be significant, particularly for educational institutions and training providers that rely on this platform for delivering online courses. Successful exploitation of this XSS vulnerability can lead to unauthorized script execution in users' browsers, enabling attackers to hijack user sessions, steal credentials or cookies, and conduct phishing or social engineering attacks within the trusted LMS environment. This can undermine user trust, lead to data breaches involving personal or academic information, and disrupt learning activities. Although the vulnerability does not directly affect system availability or integrity of backend data, the indirect consequences of compromised user accounts and potential lateral attacks can be severe. The fact that exploitation requires no authentication or user interaction increases the risk, as attackers can distribute malicious URLs widely. Organizations failing to patch may face reputational damage, compliance issues, and increased exposure to targeted attacks. The absence of known exploits in the wild currently limits immediate risk, but the public disclosure and medium CVSS score suggest a moderate threat level that warrants prompt remediation.

CWE-80Improper Neutralization of Script-Related HTML Tags in a Web Page (opens in a new tab)
Variant weaknessLikelihood of exploit: HighOWASP Top 10 A05:2025: Injection (opens in a new tab)
The product receives input from an upstream component, but it does not neutralize or incorrectly neutralizes special characters such as "<", ">", and "&" that could be interpreted as web-scripting elements when they are sent to a downstream component that processes web pages.
Implementation
Carefully check each input parameter against a rigorous positive specification (allowlist) defining the specific characters and format allowed. All input should be neutralized, not just parameters that the user is supposed to specify, but all data in the request, including hidden fields, cookies, headers, the URL…
Implementation · Output Encoding
Use and specify an output encoding that can be handled by the downstream component that is reading the output. Common encodings include ISO-8859-1, UTF-7, and UTF-8.
Implementation
With Struts, write all data from form beans with the bean's filter attribute set to true.
OWASP Cheat Sheets
Abuse Case (opens in a new tab)
Deserialization (opens in a new tab)
Cross Site Scripting Prevention (opens in a new tab)
DOM based XSS Prevention (opens in a new tab)
Injection Prevention (opens in a new tab)
OWASP ASVS 4.0.3
V1.5.1 (opens in a new tab)
V5.3.3 (opens in a new tab)
Attack patterns
XSS Targeting Non-Script Elements (opens in a new tab)
PHP Remote File Inclusion (opens in a new tab)
XSS Through HTTP Query Strings (opens in a new tab)
XSS Through HTTP Headers (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 9 Mar 2026, 17:27 UTC

WeaknessesCWE-80

Technical details

References

Community reviews

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