---
id: CVE-2026-56704
title: >-
  Adminer before 5.4.3 inserts unsanitized database server version strings into
  script tags with valid CSP nonces without proper validation
summary: >-
  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 th…
severity: medium
cvss: 6.1
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N'
cwe:
  - CWE-79
published: '2026-08-25'
updated: '2026-09-08'
sourceUpdated: '2026-09-08T20:23:49.880'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-56704'
references:
  - url: 'https://github.com/vrana/adminer/security/advisories/GHSA-h6jr-7pr6-grgj'
    label: disclosure@vulncheck.com
  - url: >-
      https://www.vulncheck.com/advisories/adminer-before-cross-site-scripting-via-mysql-version-string
    label: disclosure@vulncheck.com
tags:
  - nvd
epss: 0.00241
epssPercentile: 0.15584
ingestedAt: '2026-09-08T21:11:12.285Z'
---

## Overview

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.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.