CVE-2026-33938 is a high-severity vulnerability affecting Handlebars.js versions 4.0.0 through 4.7.8, which allows for arbitrary JavaScript execution on the server. The flaw arises from the `@partial-block` special variable being mutable within the template data context via helpers, enabling an attacker to inject a crafted Abstract Syntax Tree (AST) that is subsequently executed. Rated 8.1 HIGH (CVSSv3.1), it has a network attack vector with high attack complexity, but requires no privileges or user interaction, leading to high impact on confidentiality, integrity, and availability. There is currently no evidence of active exploitation, nor are public exploits available in Metasploit, Nuclei, or ExploitDB, though it has garnered some community discussion.
| Vendor | Product | Version(s) | CPE |
|---|---|---|---|
>= 4.0.0, < 4.7.9CPE matchmatch criteria | cpe:2.3:a:handlebarsjs:handlebars:*:*:*:*:*:node.js:*:* |
CVSS version used by this source: 3.1
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
The average CVE in this peer group has 0.0 Twitter, 0.1 Reddit, 0.1 Bluesky, 0.0 Mastodon, and 0.2 GitHub mentions.
No media coverage found for this CVE.
The average CVE in this peer group has 0.1 InfoSec Media, 0.0 Vendor Blog, and 0.0 Security Researcher mentions.