Adminer is open-source database management software. Adminer v5.4.1 and earlier has a version check mechanism where adminer.org sends signed version info via JavaScript postMessage, which the browser then POSTs to ?script=version. This endpoint lacks origin validation and accepts POST data from any source. An attacker can POST version[] parameter which PHP converts to an array. On next page load, openssl_verify() receives this array instead of string and throws TypeError, returning HTTP 500 to all users. Upgrade to Adminer 5.4.2.
{
"cna_assigner": "GitHub_M",
"osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/25xxx/CVE-2026-25892.json",
"cwe_ids": [
"CWE-20"
]
}