CVE-2026-41229: Froxlor has a PHP Code Injection via Unescaped Single Quotes in userdata.inc.php Generation (MysqlServer API)

Should you act?

Critical, preconditions apply

Severe if exploited, but exploitation needs conditions that may not apply to you. This signal is computed from CISA KEV, EPSS and CVSS data; it is not an editorial verdict.

• Not in CISA KEV, but CISA’s SSVC assessment records a public proof-of-concept, so attack code exists.
• EPSS 0.7%, percentile 52: FIRST’s model estimates a 0.7% chance of exploitation activity in the next 30 days, higher than 52% of all scored CVEs (moderate). EPSS is a probability, not a verdict.
• Needs an account (high (admin)). Exposure depends on who can log in.
• Only applies if your dependency tree includes froxlor/froxlor (Composer (PHP)) <= 2.3.5, fixed in 2.3.6. Check your lockfile, including transitive dependencies.

What it is

Froxlor is open source server administration software. Prior to version 2.3.6, PhpHelper::parseArrayToString() writes string values into single-quoted PHP string literals without escaping single quotes. When an admin with changeserversettings permission adds or updates a MySQL server via the API, the privilegeduser parameter (which has no input validation) is written unescaped into lib/userdata.inc.php. Since this file is required on every request via Database::getDB(), an attacker can inject arbitrary PHP code that executes as the web server user on every subsequent page load. Version 2.3.6 contains a patch.

From the GitHub advisory

Summary

PhpHelper::parseArrayToString() writes string values into single-quoted PHP string literals without escaping single quotes. When an admin with changeserversettings permission adds or updates a MySQL server via the API, the privilegeduser parameter (which has no input validation) is written unescaped into lib/userdata.inc.php. Since this file is required on every request via Database::getDB(), an attacker can inject arbitrary PHP code that executes as the web server user on every subsequent page load.

Details

The root cause is in PhpHelper::parseArrayToString() at lib/Froxlor/PhpHelper.php:486:

Note that the password key receives special treatment via nowdoc syntax (line 484), which is safe because nowdoc does not interpret any escape sequences or variable interpolation. However, all other string keys — including user, caption, and caFile — are written directly into single-quoted PHP string literals with no escaping.

Weakness type: CWE-94.

Product: froxlor/froxlor (Composer (PHP)) · Assigned by: GitHub_M · Published: 2026-04-23

Affected and fixed versions

Severity scores

• Attack vector: network (remotely reachable)
• Attack complexity: low
• Privileges required: high (admin)
• User interaction: none
• Scope: changed (can affect other components)

CVSS measures how bad a flaw is if exploited, not how likely exploitation is. Read it next to the exploitation data below.

Exploitation and urgency

• CISA KEV: not listed (no confirmed in-the-wild exploitation known to CISA).
• CISA SSVC assessment: exploitation poc, automatable no, technical impact total.
• FIRST EPSS (model of 2026-10-21): 0.69% probability of exploitation activity in the next 30 days; percentile 52.

Timeline

• 2026-04-16 — GitHub-reviewed advisory GHSA-gc9w-cc93-rjv8 published (critical)
• 2026-04-23 — CVE record last updated
• 2026-04-23 — CVE record published by GitHub_M

Sources and references

Original sources first. Version and fix details should always be confirmed against the vendor or project advisory.

Vulnerability records

1. GitHub Advisory GHSA-gc9w-cc93-rjv8 github.com
2. CVE.org record CVE-2026-41229 cve.org
3. NVD entry CVE-2026-41229 nvd.nist.gov

Other references from the CVE record and advisory

1. github.com github.com
2. github.com github.com
3. github.com github.com

Critical Composer (PHP) advisories · Today’s Security Digest