6.1
MEDIUM CVSS 3.1
CVE-2026-82535
Chamilo LMS Stored XSS via Survey Answer Submission in reporting.php
Description

Chamilo LMS before 1.11.42 and 3.0.0 contains a stored cross-site scripting vulnerability that allows unauthenticated attackers to inject malicious script payloads into survey answers by computing deterministic invitation codes and bypassing authorization checks in the survey submission endpoint. Attackers can submit crafted answers containing unescaped HTML rendered in reporting views to execute arbitrary scripts in the browser sessions of teachers or administrators, enabling persistent backdoor account creation by exploiting the victim's authenticated session.

INFO

Published Date :

Sept. 11, 2026, 6:16 p.m.

Last Modified :

Sept. 11, 2026, 8:19 p.m.

Remotely Exploit :

Yes !
Affected Products

The following products are affected by CVE-2026-82535 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

ID Vendor Product Action
1 Chamilo chamilo_lms
CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 134c704f-9b21-4f2e-91b3-4a467353bcc0
CVSS 3.1 MEDIUM 83251b91-4cc7-4094-a5c7-464a1b83ea10
CVSS 3.1 MEDIUM [email protected]
CVSS 4.0 MEDIUM 83251b91-4cc7-4094-a5c7-464a1b83ea10
CVSS 4.0 MEDIUM [email protected]
Solution
Update Chamilo LMS to a patched version to fix stored XSS in survey answers.
  • Update Chamilo LMS to version 1.11.42 or 3.0.0.
  • Apply vendor patches for the identified vulnerability.
  • Review survey submission and reporting configurations.
  • Sanitize all user-supplied input for surveys.
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-82535 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2026-82535 weaknesses.

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2026-82535 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2026-82535 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0

    Sep. 11, 2026

    Action Type Old Value New Value
    Added SSVC {'id': 'CVE-2026-82535', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'none'}, {'automatable': 'no'}, {'technicalImpact': 'partial'}], 'version': '2.0.3', 'timestamp': '2026-09-11T19:21:14.253000Z'}
  • New CVE Received by [email protected]

    Sep. 11, 2026

    Action Type Old Value New Value
    Added Description Chamilo LMS before 1.11.42 and 3.0.0 contains a stored cross-site scripting vulnerability that allows unauthenticated attackers to inject malicious script payloads into survey answers by computing deterministic invitation codes and bypassing authorization checks in the survey submission endpoint. Attackers can submit crafted answers containing unescaped HTML rendered in reporting views to execute arbitrary scripts in the browser sessions of teachers or administrators, enabling persistent backdoor account creation by exploiting the victim's authenticated session.
    Added CVSS V4.0 AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
    Added CVSS V3.1 AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
    Added CWE CWE-79
    Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/82xxx/CVE-2026-82535.json">CVE-2026-82535</a>
    Added Reference https://github.com/chamilo/chamilo-lms/commit/be45f2f2a29319afbbf9ce27d094698911799d10
    Added Reference https://github.com/chamilo/chamilo-lms/commit/bea9cbcfc6ca58f387c6c25bef2f15dc5df9d147
    Added Reference https://github.com/chamilo/chamilo-lms/commit/c9d2614d798571b94cef1cb61e605a2fc89f0386
    Added Reference https://github.com/chamilo/chamilo-lms/releases/tag/v3.0.0
    Added Reference https://github.com/chamilo/chamilo-lms/security/advisories/GHSA-m3wr-p8wj-jmf6
    Added Reference https://www.vulncheck.com/advisories/chamilo-lms-stored-xss-via-survey-answer-submission-in-reporting-php
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.