{"id":"CVE-2026-106446","published":"2026-10-06T20:17:26.430","lastModified":"2026-10-07T19:17:32.293","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.","cvssScore":9.8,"cvssSeverity":"CRITICAL","cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","cwes":["CWE-94","CWE-843"],"vendors":[],"products":[],"references":[{"url":"https://github.com/handlebars-lang/handlebars.js/commit/703fdcc5fd6cc8d1cc0c33cc19de40c467c4b8d2","tags":[]},{"url":"https://github.com/handlebars-lang/handlebars.js/pull/2185","tags":[]},{"url":"https://github.com/handlebars-lang/handlebars.js/releases/tag/v4.7.10","tags":[]},{"url":"https://github.com/handlebars-lang/handlebars.js/security/advisories/GHSA-8r5x-fm3f-whwj","tags":[]},{"url":"https://github.com/handlebars-lang/handlebars.js/security/advisories/GHSA-8r5x-fm3f-whwj","tags":[]}],"exploitRefs":[{"url":"https://github.com/handlebars-lang/handlebars.js/commit/703fdcc5fd6cc8d1cc0c33cc19de40c467c4b8d2","tags":[]},{"url":"https://github.com/handlebars-lang/handlebars.js/pull/2185","tags":[]},{"url":"https://github.com/handlebars-lang/handlebars.js/releases/tag/v4.7.10","tags":[]},{"url":"https://github.com/handlebars-lang/handlebars.js/security/advisories/GHSA-8r5x-fm3f-whwj","tags":[]},{"url":"https://github.com/handlebars-lang/handlebars.js/security/advisories/GHSA-8r5x-fm3f-whwj","tags":[]}],"hasPoc":true,"ai":{"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.","remediation":"Upgrade to Handlebars version 4.7.10 or later.","detection":"No reliable host or network indicator is derivable from the published description.","tags":["rce","web","template-injection"],"model":"qwen2.5:7b-instruct","analyzedAt":"2026-10-07T08:43:28.876Z"}}