Scriban before 7.0.0 (affected <= 6.6.0) applies its LoopLimit constraint only to script loop statements and not to expensive iteration performed inside built-in operators and functions. As a result, a single expression such as {{ 1..1000000 | array.size }} — or a memory-amplification expression such as {{ 'A' * 200000000 }} — can force large CPU or memory consumption even when LoopLimit is configured to a very small value, resulting in denial of service. Applications that render attacker-controlled templates and rely on LoopLimit for safe execution are affected.
https://www.vulncheck.com/advisories/scriban-before-looplimit-bypass-via-built-in-operations
https://github.com/scriban/scriban/security/advisories/GHSA-c875-h985-hvrc
Published: 2026-08-16
Updated: 2026-08-16
Base Score: 7.8
Vector: CVSS2#AV:N/AC:L/Au:N/C:N/I:N/A:C
Severity: High
Base Score: 7.5
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Severity: High
Base Score: 8.7
Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
Severity: High