CVE-2026-34429: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') in givanz Vvveb
Vvveb prior to 1.0.8.1 contains a stored cross-site scripting vulnerability that allows authenticated users with media upload and rename permissions to execute arbitrary JavaScript by bypassing MIME type validation and renaming uploaded files to executable extensions. Attackers can prepend a GIF89a header to HTML/JavaScript payloads to bypass upload validation, rename the file to .html extension, and execute malicious scripts in an administrator's browser session to create backdoor accounts and upload malicious plugins for remote code execution.
AI Analysis
Technical Summary
CVE-2026-34429 is a stored cross-site scripting vulnerability in givanz Vvveb before version 1.0.8.1. The vulnerability arises because the application fails to properly neutralize input during web page generation. Attackers with authenticated media upload and rename permissions can bypass MIME type validation by prepending a GIF89a header to HTML/JavaScript payloads, then rename the files to .html extensions. This enables execution of arbitrary JavaScript in an administrator's browser session, which can be leveraged to create backdoor accounts and upload malicious plugins, potentially leading to remote code execution.
Potential Impact
Successful exploitation allows an authenticated user with specific permissions to execute arbitrary JavaScript in an administrator's session. This can lead to privilege escalation through creation of backdoor accounts and uploading of malicious plugins, which may result in remote code execution. The CVSS 4.0 base score is 5.1, indicating a medium severity vulnerability with network attack vector, low complexity, and limited scope impact.
Mitigation Recommendations
No official patch or remediation is currently confirmed. Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until a fix is available, restrict media upload and rename permissions to trusted users only and monitor for suspicious activity related to file uploads and renaming.
CVE-2026-34429: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') in givanz Vvveb
Description
Vvveb prior to 1.0.8.1 contains a stored cross-site scripting vulnerability that allows authenticated users with media upload and rename permissions to execute arbitrary JavaScript by bypassing MIME type validation and renaming uploaded files to executable extensions. Attackers can prepend a GIF89a header to HTML/JavaScript payloads to bypass upload validation, rename the file to .html extension, and execute malicious scripts in an administrator's browser session to create backdoor accounts and upload malicious plugins for remote code execution.
CVSS v4.0
Score 5.1medium
Affected software
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Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
CVE-2026-34429 is a stored cross-site scripting vulnerability in givanz Vvveb before version 1.0.8.1. The vulnerability arises because the application fails to properly neutralize input during web page generation. Attackers with authenticated media upload and rename permissions can bypass MIME type validation by prepending a GIF89a header to HTML/JavaScript payloads, then rename the files to .html extensions. This enables execution of arbitrary JavaScript in an administrator's browser session, which can be leveraged to create backdoor accounts and upload malicious plugins, potentially leading to remote code execution.
Potential Impact
Successful exploitation allows an authenticated user with specific permissions to execute arbitrary JavaScript in an administrator's session. This can lead to privilege escalation through creation of backdoor accounts and uploading of malicious plugins, which may result in remote code execution. The CVSS 4.0 base score is 5.1, indicating a medium severity vulnerability with network attack vector, low complexity, and limited scope impact.
Mitigation Recommendations
No official patch or remediation is currently confirmed. Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until a fix is available, restrict media upload and rename permissions to trusted users only and monitor for suspicious activity related to file uploads and renaming.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- VulnCheck
- Date Reserved
- 2026-03-27T15:24:06.752Z
- Cvss Version
- 4.0
- State
- PUBLISHED
- Remediation Level
- null
Threat ID: 69e6390b19fe3cd2cd03286a
Added to database: 04/20/2026, 14:32:43 UTC
Last enriched: 07/30/2026, 00:34:30 UTC
Last updated: 07/31/2026, 21:26:47 UTC
Views: 112
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