{"id":"CVE-2026-33937","title":"Handlebars provides the power necessary to let users build semantic templates","summary":"Handlebars provides the power necessary to let users build semantic templates. In versions 4.0.0 through 4.7.8, `Handlebars.compile()` accepts a pre-parsed AST object in addition to a template string. The `value` field of a `NumberLitera…","severity":"critical","cvss":9.8,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","cwe":["CWE-94","CWE-843","CWE-94"],"vendor":"handlebarsjs","product":"handlebars","affected":["handlebars >= 4.0.0, < 4.7.9"],"patched":["handlebars 4.7.9"],"published":"2026-03-27","updated":"2026-07-02","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-33937","references":[{"url":"https://github.com/handlebars-lang/handlebars.js/commit/68d8df5a88e0a26fe9e6084c5c6aaebe67b07da2","label":"security-advisories@github.com"},{"url":"https://github.com/handlebars-lang/handlebars.js/releases/tag/v4.7.9","label":"security-advisories@github.com"},{"url":"https://github.com/handlebars-lang/handlebars.js/security/advisories/GHSA-2w6w-674q-4c4q","label":"security-advisories@github.com"},{"url":"https://access.redhat.com/errata/RHSA-2026:10175","label":"0b0ca135-0b70-47e7-9f44-1890c2a1c46c"},{"url":"https://access.redhat.com/errata/RHSA-2026:34342","label":"0b0ca135-0b70-47e7-9f44-1890c2a1c46c"},{"url":"https://access.redhat.com/security/cve/CVE-2026-33937","label":"0b0ca135-0b70-47e7-9f44-1890c2a1c46c"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2452523","label":"0b0ca135-0b70-47e7-9f44-1890c2a1c46c"},{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-33937.json","label":"0b0ca135-0b70-47e7-9f44-1890c2a1c46c"}],"tags":["nvd","exploit-available"],"epss":0.01704,"epssPercentile":0.76251,"ingestedAt":"2026-07-02T12:34:40.401Z","exploits":{"github":4,"githubRepos":["https://github.com/dinhvaren/cve-2026-33937","https://github.com/EQSTLab/CVE-2026-33937","https://github.com/garlic-wizard/CVE-2026-33937-for-DarkZeroReturns"],"checkedAt":"2026-09-23T07:13:59.453Z"},"exploitAvailable":true,"slug":"CVE-2026-33937","body":"## Overview\n\nHandlebars provides the power necessary to let users build semantic templates. In versions 4.0.0 through 4.7.8, `Handlebars.compile()` accepts a pre-parsed AST object in addition to a template string. The `value` field of a `NumberLiteral` AST node is emitted directly into the generated JavaScript without quoting or sanitization. An attacker who can supply a crafted AST to `compile()` can therefore inject and execute arbitrary JavaScript, leading to Remote Code Execution on the server. Version 4.7.9 fixes the issue. Some workarounds are available. Validate input type before calling `Handlebars.compile()`; ensure the argument is always a  `string`, never a plain object or JSON-deserialized value. Use the Handlebars runtime-only build (`handlebars/runtime`) on the server if templates are pre-compiled at build time; `compile()` will be unavailable.\n\n## Affected\n\n- `handlebars >= 4.0.0, < 4.7.9`\n\n## Remediation\n\nUpgrade past the affected range:\n\n- `handlebars 4.7.9`","depth":"abyssal","depthScore":66,"depthScoreParts":{"impact":53.9,"likelihood":0.3,"exploitation":12,"ransomware":0},"changes":[{"seq":5117,"id":"CVE-2026-33937","ts":1788887248874,"field":"exploit_available","old":"false","new":"true"},{"seq":4000,"id":"CVE-2026-33937","ts":1788886364547,"field":"exploit_available","old":"true","new":"false"},{"seq":2813,"id":"CVE-2026-33937","ts":1788883031249,"field":"exploit_available","old":"false","new":"true"},{"seq":1842,"id":"CVE-2026-33937","ts":1788882434172,"field":"exploit_available","old":"true","new":"false"},{"seq":940,"id":"CVE-2026-33937","ts":1788881868195,"field":"exploit_available","old":"false","new":"true"}]}