Vulnerability · Published Aug 25, 2026 · Assigned by VulnCheck

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

Medium 6.1

In plain English

A medium-severity cross-site scripting in adminer from vrana. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 27% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)6.1Medium

Exploit odds (30 days)0.3%top 72.8% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

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.

Affected packages & fixed versions

Ecosystem	Package	Fixed in	Advisory
Debian:12	adminer	no fix listed	DEBIAN-CVE-2026-56704
Debian:13	adminer	no fix listed	DEBIAN-CVE-2026-56704
Debian:14	adminer	5.4.3+dfsg-1	DEBIAN-CVE-2026-56704
Ubuntu:22.04:LTS	adminer	no fix listed	UBUNTU-CVE-2026-56704
Ubuntu:24.04:LTS	adminer	no fix listed	UBUNTU-CVE-2026-56704
Ubuntu:26.04:LTS	adminer	no fix listed	UBUNTU-CVE-2026-56704

Affected products (as reported)

Vendor	Product	Versions
vrana	adminer	0 – before 5.4.3

Weakness: CWE-79 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

References

GitHub Security Advisory (GHSA-h6jr-7pr6-grgj) vendor-advisory
VulnCheck Advisory: Adminer before 5.4.3 Cross-Site Scripting via MySQL Version String third-party-advisory