CVE-2025-26153Public exploitNetwork attack vector

Session hijacking via unsanitized message content

Published Apr 16, 2025 · Updated Apr 18, 2025

Stored XSS in Chamilo LMS 1.11.28 allows remote authenticated users to execute scripts in a recipient's browser through a crafted message. The message composer stores unescaped HTML from its image Alternative Text and Insert HTML controls, while reply rendering executes embedded event-handler markup. An account that can send messages and a recipient who replies are required; execution can expose the recipient's session cookie.

CVSS severity5.4
Medium
EPSS probability0.34%
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 1.11.28 allows remote authenticated users to execute scripts in a recipient's browser through a crafted message. The message composer stores unescaped HTML from its image Alternative Text and Insert HTML controls, while reply rendering executes embedded event-handler markup. An account that can send messages and a recipient who replies are required; execution can expose the recipient's session cookie.

The record

CVE
CVE-2025-26153
Published
Apr 16, 2025
Updated
Apr 18, 2025
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-79, T1539
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Apr 16, 2025CVE publishedPublication date reported by the CVE source.
  2. Apr 18, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

5.4CISA-ADPCVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N

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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
T1539Steal Web Session Cookie

Public exploit references

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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