CVE-2026-56704: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') in vrana adminer
Description
CVE-2026-56704 is a cross-site scripting (XSS) vulnerability in Adminer before version 5.4.3. The issue arises because unsanitized database server version strings are inserted into script tags with valid Content Security Policy (CSP) nonces without proper validation. This allows an attacker controlling a rogue MySQL server to craft malicious version strings that break out of the JavaScript context and execute arbitrary code, bypassing CSP protections.
CVSS v4.0
Score 5.3medium
Affected software
vrana
adminer
Run on your own infrastructure? Check whether these packages are installed with threat-finder — our free open-source scanner.
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
Adminer versions prior to 5.4.3 improperly neutralize input during web page generation by inserting unsanitized database server version strings into script tags that use valid CSP nonces. This vulnerability enables attackers who control a malicious MySQL server to return specially crafted version strings that escape the JavaScript context, leading to arbitrary code execution in the client browser. The vulnerability bypasses CSP protections due to the use of valid nonces but lack of input validation.
Potential Impact
An attacker controlling a rogue MySQL server can exploit this vulnerability to execute arbitrary JavaScript code in the context of the Adminer web application. This can lead to client-side code execution despite Content Security Policy protections, potentially resulting in session hijacking, data theft, or other malicious actions within the user's browser session.
Mitigation Recommendations
A fix is available in Adminer version 5.4.3. Users should upgrade to version 5.4.3 or later to remediate this vulnerability. No additional mitigation steps are indicated in the provided data.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- VulnCheck
- Date Reserved
- 2026-06-22T18:48:27.059Z
- Cvss Version
- 4.0
- State
- PUBLISHED
Threat ID: 6a8cf57aacd9273b49842869
Added to database: 08/25/2026, 01:52:58 UTC
Last enriched: 09/10/2026, 20:47:41 UTC
Last updated: 10/07/2026, 18:48:21 UTC
Views: 64
Community Reviews
0 reviewsCrowdsource mitigation strategies, share intel context, and vote on the most helpful responses. Sign in to add your voice and help keep defenders ahead.
Want to contribute mitigation steps or threat intel context? Sign in or create an account to join the community discussion.
Actions
Updates to AI analysis require Pro Console access. Upgrade inside Console → Billing.
Need more coverage?
Upgrade to Pro Console for AI refresh and higher limits.
For incident response and remediation, OffSeq services can help resolve threats faster.
Latest Threats
Check if your credentials are on the dark web
Instant breach scanning across billions of leaked records. Free tier available.