CVE-2026-45357

Summary

LiquidJS is a Shopify/GitHub Pages compatible template engine written in pure JavaScript. In versions 10.25.7 and below, the date filter's strftime implementation parses width specifiers like %9999999

Details

LiquidJS is a Shopify/GitHub Pages compatible template engine written in pure JavaScript. In versions 10.25.7 and below, the date filter's strftime implementation parses width specifiers like %9999999d and forwards the captured width unchecked into pad()/padStart(), leading to memory and render limit bypass. In src/util/underscore.ts, the pad loop performs unbounded string concatenation without consulting the Context's memoryLimit or renderLimit, so a single small template ({{ x | date: '%5000000d' }}) produces megabytes of output and unbounded CPU. The memoryLimit and renderLimit options the docs (src/liquid-options.ts:87-92) advertise as DoS controls — and which the docstring explicitly mentions for strftime — are entirely bypassed. Exploitation can cause large memory allocations, high CPU usage, or OOM crashes per render. This issue has been fixed in version 10.26.0.

References

• https://github.com/harttle/liquidjs/commit/3129d46dc95efa357b00e5a57ee1af80a13d72ed
• https://github.com/harttle/liquidjs/releases/tag/v10.26.0
• https://github.com/harttle/liquidjs/security/advisories/GHSA-hh27-hf48-9f5q
• https://github.com/harttle/liquidjs/security/advisories/GHSA-hh27-hf48-9f5q