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.
https://www.vulncheck.com/advisories/vvveb-stored-xss-via-media-upload-and-rename
https://github.com/givanz/Vvveb/releases/tag/1.0.8.1
https://github.com/givanz/Vvveb/commit/cc997d3359ea5e49a45c132f5dee3bc80fb441d7
https://delta.cyberm.ca/bugbin/ur66bvB7BYTC9y0eCIk3uzhZQgbjzAkG/
Published: 2026-04-20
Updated: 2026-04-20
Base Score: 5.5
Vector: CVSS2#AV:N/AC:L/Au:S/C:P/I:P/A:N
Severity: Medium
Base Score: 5.4
Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N
Severity: Medium
Base Score: 5.1
Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N
Severity: Medium