Twig is a template language for PHP. From 3.9.0 until 3.26.0, template_from_string() compiles an inner template under a synthesized string_template<hash> name that can fall outside a SourcePolicyInterface sandbox decision, allowing a sandboxed template that can call template_from_string and include to render an inner template without security policy enforcement. This issue is fixed in version 3.26.0.
Exploitability
AV:NAC:LAT:PPR:LUI:NVulnerable System
VC:HVI:HVA:HSubsequent System
SC:NSI:NSA:N7.7/CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:NOther