# CVE-2026-54506: Vvveb: Stored XSS via sanitizeHTML() bypass in user profile bio field

> Stored XSS in Vvveb CMS allows attackers to execute JavaScript via the user bio field, potentially leading to session hijacking or account takeover.

- **Severity:** High 7.6 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:L/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** No
- **Published:** 17 Sep 2026
- **Updated:** 23 Sep 2026
- **Also known as:** GHSA-5cg7-phhv-4qjr

## What is CVE-2026-54506?

CVE-2026-54506 is a high-severity cross-site scripting vulnerability in givanz Vvveb, published on 17 Sep 2026. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.

### Official description

Vvveb is a powerful and easy to use CMS with page builder to build websites, blogs or ecommerce stores. Prior to 1.0.8.5, app/controller/user/profile.php accepts the user[bio] field and passes stored content through sanitizeHTML() in system/functions.php, whose on* event-handler regular expression omits the forward-slash delimiter and whose do-while condition compares the string to itself, so forbidden nested tags are removed only once. An Author-role or higher user can submit solidus-prefixed event-handler markup or nested forbidden tags that survive sanitization. The stored bio is rendered without sufficient output encoding on /author/{username}, in the admin user-management view, and potentially in comment displays, causing attacker-controlled JavaScript to execute when unauthenticated visitors, administrators, or other users view the content. This can expose browser-session data and permit victim-context account actions, defacement, or phishing. This issue is fixed in version 1.0.8.5.

Weakness: CWE-79 (Improper Neutralization of Input During Web Page Generation), CWE-185 (Incorrect Regular Expression), CWE-116 (Improper Encoding or Escaping of Output)

## Which versions are affected by CVE-2026-54506?


## How do I fix CVE-2026-54506?

No fix has been published for CVE-2026-54506 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-54506 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-54506 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-54506 and fix it if it is affected.

What it is: CVE-2026-54506 is a high-severity cross-site scripting vulnerability in givanz Vvveb, published on 17 Sep 2026. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-54506 exists.

Affected product: givanz Vvveb. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-54506/ (Markdown: https://insights.sbomify.com/CVE-2026-54506/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-54506
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-54506
- OSV: https://osv.dev/vulnerability/CVE-2026-54506

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From sbomify Insights: https://insights.sbomify.com/CVE-2026-54506/
Summaries are generated and may contain mistakes; the official description above is the record.