CVE-2026-109449: symfony 0 to before v5.4.54, v6.0.0-BETA1 to before v6.4.48, v7.0.0-BETA1 to before v7.4.21, v8.0.0-BETA1 to before…

Affected technology

symfony · 0 to before v5.4.54, v6.0.0-BETA1 to before v6.4.48, v7.0.0-BETA1 to before v7.4.21, v8.0.0-BETA1 to before v8.1.9
sensiolabs

Description’s affected range: versions prior to 5.4.54

Component: ExpressionLanguage::lint()

Attack conditions (Source advisory, CVSS 4.0): Network (remote) · No privileges required · No user interaction required

What an attacker can do

An application validating expressions written by its users could be crashed by a single request, and so could any code parsing untrusted expressions. Source advisory’s CVSS 4.0 assessment (base score 8.7/10) rates confidentiality and integrity impact as none; availability impact as high.