# CVE-2026-56704: Adminer before 5.4.3 Cross-Site Scripting via MySQL Version String

> Attackers can execute arbitrary code in Adminer by exploiting unsanitized MySQL version strings, bypassing CSP protections.

- **Severity:** Medium 5.3 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:L/VI:L/VA:N/SC:L/SI:L/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** Yes
- **Published:** 25 Aug 2026
- **Updated:** 26 Aug 2026
- **Also known as:** DEBIAN-CVE-2026-56704, GHSA-gx46-wch5-wp5p, GHSA-h6jr-7pr6-grgj, UBUNTU-CVE-2026-56704

## What is CVE-2026-56704?

CVE-2026-56704 is a medium-severity cross-site scripting vulnerability in vrana adminer, published on 25 Aug 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

### Official description

Adminer before 5.4.3 inserts unsanitized database server version strings into script tags with valid CSP nonces without proper validation. Attackers controlling a rogue MySQL server can return crafted version strings that break out of the JavaScript context and execute arbitrary code, bypassing Content Security Policy protections.

Weakness: CWE-79 (Improper Neutralization of Input During Web Page Generation)

## Which versions are affected by CVE-2026-56704?


## How do I fix CVE-2026-56704?

Upgrade to a fixed version.

## Is CVE-2026-56704 being exploited?

There is no known exploitation of CVE-2026-56704 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-56704 and fix it if it is affected.

What it is: CVE-2026-56704 is a medium-severity cross-site scripting vulnerability in vrana adminer, published on 25 Aug 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2026-56704 in the wild and no public exploit code.

Affected product: vrana adminer. 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-2026-56704/ (Markdown: https://insights.sbomify.com/CVE-2026-56704/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-56704
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-56704
- OSV: https://osv.dev/vulnerability/CVE-2026-56704

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-56704/
Summaries are generated and may contain mistakes; the official description above is the record.