Description
Handlebars provides the power necessary to let users build semantic templates. In versions 4.0.0 through 4.7.8, the `@partial-block` special variable is stored in the template data context and is reachable and mutable from within a template via helpers that accept arbitrary objects. When a helper overwrites `@partial-block` with a crafted Handlebars AST, a subsequent invocation of `{{> @partial-block}}` compiles and executes that AST, enabling arbitrary JavaScript execution on the server. Version 4.7.9 fixes the issue. Some workarounds are available. First, use the runtime-only build (`require('handlebars/runtime')`). The `compile()` method is absent, eliminating the vulnerable fallback path. Second, audit registered helpers for any that write arbitrary values to context objects. Helpers should treat context data as read-only. Third, avoid registering helpers from third-party packages (such as `handlebars-helpers`) in contexts where templates or context data can be influenced by untrusted input.
INFO
Published Date :
2026-03-27T21:05:42.485Z
Last Modified :
2026-03-27T21:05:42.485Z
Source :
GitHub_M
AFFECTED PRODUCTS
The following products are affected by CVE-2026-33938 vulnerability.
No data.
REFERENCES
Here, you will find a curated list of external links that provide in-depth information to CVE-2026-33938.
