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.
- 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
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
Which versions are affected by CVE-2026-56704?
How do I fix CVE-2026-56704?
Upgrade to a fixed version.
Escape output for the context it lands in and set a strict Content Security Policy. Upgrading the affected component is the real fix. More about Cross-site scripting.
Is CVE-2026-56704 being exploited?
There is no known exploitation of CVE-2026-56704 in the wild and no public exploit code.
Sources
Also known as DEBIAN-CVE-2026-56704, GHSA-gx46-wch5-wp5p, GHSA-h6jr-7pr6-grgj, UBUNTU-CVE-2026-56704.