CVE-2026-106446
9.8 CRITICALpublic exploit availablePublished 2026-10-06 · Updated 2026-10-07
AI risk analysis
- Summary
- This flaw allows attackers to inject JavaScript code into Handlebars templates, leading to remote code execution. It matters because it can be exploited to gain unauthorized access and control over the server process.
- Exploitability
- Exploitation requires the attacker to supply an object containing JavaScript expressions, which is moderately difficult given the need for template manipulation capabilities.
- Blast radius
- If exploited, this can result in full server compromise, potentially affecting all users and services running on the server.
- Detection
- No reliable host or network indicator is derivable from the published description.
- Prioritized remediation
- Upgrade to Handlebars version 4.7.10 or later.
Analysis generated locally by qwen2.5:7b-instruct (no data left the box). AI-assisted — verify against primary sources before acting.
NVD description
Handlebars provides the power necessary to let users build semantic templates. From 4.0.0 until 4.7.10, Handlebars.compile() and Handlebars.precompile() accept pre-parsed AST objects while validating only selected PathExpression, NumberLiteral, and BooleanLiteral values. This issue bypasses the AST validation introduced in version 4.7.9 for CVE-2026-33937. An attacker who can supply an object instead of a template string can place JavaScript expressions in unchecked values such as Program.blockParams.length, a non-PathExpression parameter depth, a non-string StringLiteral.value, or a non-string PathExpression.original. The compiler emits those values into generated JavaScript, causing code execution in the server process when compile output renders or wherever precompile output is loaded. Applications that pass only template strings are not affected. This issue is fixed in version 4.7.10.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Weaknesses
CWE-94, CWE-843
Public exploit & PoC references
- https://github.com/handlebars-lang/handlebars.js/commit/703fdcc5fd6cc8d1cc0c33cc19de40c467c4b8d2
- https://github.com/handlebars-lang/handlebars.js/pull/2185
- https://github.com/handlebars-lang/handlebars.js/releases/tag/v4.7.10
- https://github.com/handlebars-lang/handlebars.js/security/advisories/GHSA-8r5x-fm3f-whwj
- https://github.com/handlebars-lang/handlebars.js/security/advisories/GHSA-8r5x-fm3f-whwj
All references
- https://github.com/handlebars-lang/handlebars.js/commit/703fdcc5fd6cc8d1cc0c33cc19de40c467c4b8d2
- https://github.com/handlebars-lang/handlebars.js/pull/2185
- https://github.com/handlebars-lang/handlebars.js/releases/tag/v4.7.10
- https://github.com/handlebars-lang/handlebars.js/security/advisories/GHSA-8r5x-fm3f-whwj
- https://github.com/handlebars-lang/handlebars.js/security/advisories/GHSA-8r5x-fm3f-whwj
Source data: NVD (nvd.nist.gov), public domain. Exploit-DB.ai adds local AI analysis for defensive use only.
Related CVEs
- CRITICALCVE-2026-108598PoC
- HIGHCVE-2026-79310PoC
- HIGHCVE-2026-82531PoC
- CRITICALCVE-2026-103849
- CRITICALCVE-2026-108264PoC
- CRITICALCVE-2026-111687PoC
- HIGHCVE-2026-12370
- CRITICALCVE-2026-55240PoC
Related by shared AI tags and CWE weakness class. Browse the full archive.