CVE-2026-59989

Phalcon Volt compiler `join` filter compile-time PHP code injection (SSTI lead to RCE)

State: Published
Severity: 9.2 Critical
Published: Aug 21, 2026
Updated: Aug 27, 2026
Reserved: Jul 7, 2026

Description

Phalcon is a high-performance, full-stack PHP framework. In 5.15.0 and earlier, resolveFilter in phalcon/Mvc/View/Engine/Volt/Compiler.zep builds the join filter by inserting the raw separator and array token values into generated PHP without passing them through expression(). An attacker who can influence Volt template source can place quote-breaking content in a join argument, inject PHP into the compiled cache file, and execute it when Phalcon\Mvc\View\Engine\Volt::render() loads the template. This issue is fixed in version 5.16.0.

Scores

CVSS	Score	Vector	Source
4.0	9.2 Critical	CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N	GitHub_M

Weaknesses

CWE-94 Improper Control of Generation of Code ('Code Injection')
CWE-1336 Improper Neutralization of Special Elements Used in a Template Engine

Affected Products

Product	Versions
cphalconphalcon	< 5.16.0Affected

References

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