CVE-2026-113683: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') in jcrodriguez-dis moodle-mod_vpl
Description
A reflected cross-site scripting (XSS) vulnerability exists in the VPL (Virtual Programming Lab) plugin for Moodle versions before 5.0.0. This flaw allows remote attackers to inject malicious scripts via unencoded filename1 and filename2 parameters in the similarity/diff.php page. When a user with the mod/vpl:similarity capability opens a crafted diff.php link, the injected script executes in their session context, potentially enabling unauthorized actions or data disclosure.
CVSS v4.0
Score 5.1medium
Affected software
jcrodriguez-dis
moodle-mod_vpl
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AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
CVE-2026-113683 describes a reflected XSS vulnerability in the moodle-mod_vpl plugin prior to version 5.0.0. The vulnerability arises from improper neutralization of input in the similarity/diff.php script, specifically via the filename1 and filename2 parameters which are not properly encoded. An attacker can craft a URL containing JavaScript payloads in these parameters that execute when a user with the mod/vpl:similarity permission accesses the link, leading to script execution in the victim's browser session.
Potential Impact
Successful exploitation allows remote attackers to execute arbitrary JavaScript in the context of the victim's browser session when they open a maliciously crafted diff.php URL. This can lead to unauthorized actions or disclosure of sensitive information accessible to the victim's session. The vulnerability requires user interaction and the victim must have the mod/vpl:similarity capability, limiting the scope somewhat.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until an official fix is available, users should avoid opening untrusted similarity/diff.php links and restrict mod/vpl:similarity capability to trusted users only.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- VulnCheck
- Date Reserved
- 2026-10-20T14:51:03.227Z
- Cvss Version
- 4.0
- State
- PUBLISHED
Threat ID: 6ad78d892cdf04f6563d770a
Added to database: 10/20/2026, 15:49:29 UTC
Last enriched: 10/20/2026, 16:03:57 UTC
Last updated: 10/20/2026, 16:04:18 UTC
Views: 5
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