CVE-2026-82535Network attack vector

Stored XSS via unescaped survey answers

Published Sep 11, 2026 · Updated Sep 11, 2026

Stored XSS in Chamilo LMS before 1.11.42 and 3.0.0 allows remote attackers to execute scripts through crafted survey answers. The survey submission endpoint accepts answers under deterministic invitation codes without authorization, while reporting views render their HTML without escaping. A teacher or administrator must view the stored answer; the script then runs in that authenticated browser session and can create persistent backdoor accounts.

CVSS severityUnavailable
Unscored
EPSS probability0.27%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Stored XSS in Chamilo LMS before 1.11.42 and 3.0.0 allows remote attackers to execute scripts through crafted survey answers. The survey submission endpoint accepts answers under deterministic invitation codes without authorization, while reporting views render their HTML without escaping. A teacher or administrator must view the stored answer; the script then runs in that authenticated browser session and can create persistent backdoor accounts.

The record

CVE
CVE-2026-82535
Published
Sep 11, 2026
Updated
Sep 11, 2026
Vendor
Chamilo
Product
Chamilo LMS
Classifications
T1098
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Sep 11, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 11, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=1.11.0 <=1.11.40
  2. Affected versionversion=2.0.0 <=2.0.3

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Chamilo · Chamilo LMSversion=1.11.0 <=1.11.40; version=2.0.0 <=2.0.3

Published CVSS scores

No CVSS assessment is available in this record.

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

T1098Account Manipulation

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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