XSS in Givanz Vvveb
CVE-2026-34429
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.
Vulnerability class: XSS (Cross-Site Scripting)
Published · last modified .
CVSS v3 metric
CVSS v3 base score 5.4 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N.
EPSS exploit prediction
EPSS: 0.005 (38.9th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 39th percentile — 38.9% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.003 · newest: 0.005 · change: +0.002
Affected products
- Givanz Vvveb — versions 0, cc997d3359ea5e49a45c132f5dee3bc80fb441d7
Weakness classification (CWE)
References
- delta.cyberm.ca/bugbin/ur66bvB7BYTC9y0eCIk3uzhZQgbjzAkG/ (technical-description, exploit)
- github.com/givanz/Vvveb/releases/tag/1.0.8.1 (release-notes)
- github.com/givanz/Vvveb/commit/cc997d3359ea5e49a45c132f5dee3bc80fb441d7 (patch)
- www.vulncheck.com/advisories/vvveb-stored-xss-via-media-upload-and-rename (third-party-advisory)
- github.com/givanz/Vvveb/security/advisories/GHSA-2vc4-49hq-g7f4 (vendor-advisory)
Frequently asked questions
- What is CVE-2026-34429?
- CVE-2026-34429 is a medium-severity vulnerability in Givanz Vvveb, classified under Cross-site Scripting. CVSS score: 5.4/10. Published 2026-04-20.
- How severe is CVE-2026-34429?
- Medium severity. CVSS v3 base score is 5.4 out of 10.