CVE-2026-56704Public exploitNetwork attack vectorHinoki check available

Cross-site scripting via unvalidated server version

Published Aug 25, 2026 · Updated Aug 26, 2026

Cross-site scripting in Adminer before 5.4.3 allows remote attackers to execute JavaScript through a rogue MySQL server version string. In adminer.inc.php, a failed version-prefix regex returns the entire server_info value and inserts it unescaped into a nonce-bearing script call. Exploitation requires a victim browser to log in to an attacker-controlled reachable MySQL server, directly or through login CSRF, and the script runs in the Adminer origin despite CSP.

CVSS severity5.3
Medium
EPSS probability0.24%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkAvailable
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Summary

What happened

Cross-site scripting in Adminer before 5.4.3 allows remote attackers to execute JavaScript through a rogue MySQL server version string. In adminer.inc.php, a failed version-prefix regex returns the entire server_info value and inserts it unescaped into a nonce-bearing script call. Exploitation requires a victim browser to log in to an attacker-controlled reachable MySQL server, directly or through login CSRF, and the script runs in the Adminer origin despite CSP.

The record

CVE
CVE-2026-56704
Published
Aug 25, 2026
Updated
Aug 26, 2026
Vendor
Adminer
Product
Adminer
Classifications
CWE-79, CWE-352, T1203
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 25, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 26, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0 <5.4.3

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Adminer · Adminerversion=0 <5.4.3

Published CVSS scores

6.1vrana/adminerCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
5.3VulnCheckCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:L/VI:L/VA:N/SC:L/SI:L/SA:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
CWE-352Cross-Site Request Forgery (CSRF)
T1203Exploitation for Client Execution

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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