{"answers":{"affected":"2 open source packages ship an affected version, including handlebars. It affects 1 product.","exploited":"It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-33937 exists.","fix":"Upgrade handlebars to 4.7.9 or later.","what":"CVE-2026-33937 is a critical code injection vulnerability in handlebars-lang handlebars.js, published on 27 Mar 2026. An attacker can exploit it over the internet without logging in, with no action from the victim."},"fix_prompt":"Check this codebase for CVE-2026-33937 and fix it if it is affected.\n\nWhat it is: CVE-2026-33937 is a critical code injection vulnerability in handlebars-lang handlebars.js, published on 27 Mar 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.\nExploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-33937 exists.\n\nAffected packages and fixed versions:\n- handlebars (npm): affected from 4.0.0; fixed in 4.7.9\n- handlebars (npm): affected from 4.0.0; fixed in 4.7.9\n\nTask:\n1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.\n2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.\n3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.\n4. Run the tests and summarise what changed and why.\n5. If nothing in the project is affected, say so and change nothing.\n\nReference: https://insights.sbomify.com/CVE-2026-33937/ (Markdown: https://insights.sbomify.com/CVE-2026-33937/index.md)","id":"CVE-2026-33937","markdown":"https://insights.sbomify.com/CVE-2026-33937/index.md","name":"CVE-2026-33937","record":{"aliases":["CLEANSTART-2026-CI51547","CLEANSTART-2026-EC90376","DEBIAN-CVE-2026-33937","GHSA-2w6w-674q-4c4q","MINI-37rx-w7wh-w67x","MINI-53pg-78mf-c5ff","MINI-5fww-rj9q-fjcq","MINI-84jv-48jx-3qm8","MINI-8558-8pvv-9fpm","MINI-94f5-7v9q-fvf2","MINI-998w-x4qq-4w8r","MINI-9qv2-gpmp-359w","MINI-mj85-qqw3-hqwf","MINI-pg4v-xpqq-gvqj","MINI-pmjw-7gvq-vjqc","MINI-q54m-2xqh-fr2j","MINI-rm23-vwm5-8498","MINI-vgc4-8v2f-9jpj","ROOT-APP-NPM-CVE-2026-33937","UBUNTU-CVE-2026-33937"],"analysis":{"component_type":"library","fix_type":"upgrade","impacts":["code_execution"],"network_reachable":"yes","non_default_config":false,"product_category":"JavaScript templating library","requires_auth":"none","summary":"Attackers can inject arbitrary JavaScript into Handlebars templates via crafted AST objects, leading to remote code execution on the server.","user_interaction":"not_required","vuln_class":"code_injection"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"GitHub_M","cpe":[{"product":"handlebars","vendor":"handlebarsjs"}],"cvss":{"score":9.8,"severity":"critical","source":"cna","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","version":"3.1"},"cwes":[{"id":"CWE-94","name":"Improper Control of Generation of Code"},{"id":"CWE-843","name":"Access of Resource Using Incompatible Type"}],"description":"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 `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.","ecosystems":["npm"],"exploits":{"exploitdb":0,"first_seen":"2026-03-28","github_poc":4,"max_poc_stars":3,"metasploit":0,"nuclei":0,"refs":[{"date":"2026-04-22T05:09:10Z","kind":"github_poc","ref":"https://github.com/EQSTLab/CVE-2026-33937","stars":3,"title":"Handlebars.js AST Injection Remote Code Execution Vulnerability"},{"date":"2026-08-03T06:27:58Z","kind":"github_poc","ref":"https://github.com/c0gnit00/CVE-2026-33937","stars":1,"title":"Python POC, Exploit for Handlebars.js AST Injection RCE, Handlebars.js versions 4.0.0 through 4.7.8 are affected. CVSS score: 9.8 Critical."},{"date":"2026-03-28T13:24:22Z","kind":"github_poc","ref":"https://github.com/dinhvaren/cve-2026-33937","stars":0,"title":"CVE-2026-33937 Handlebars RCE exploit PoC (AST Injection)"},{"date":"2026-07-30T20:23:32Z","kind":"github_poc","ref":"https://github.com/garlic-wizard/CVE-2026-33937-for-DarkZeroReturns","stars":0,"title":"this is a poc for CVE-2026-33937 "}],"tier":"weaponised"},"has_fix":true,"headline":"Handlebars.js has JavaScript Injection via AST Type Confusion","id":"CVE-2026-33937","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":"npm","product":null,"products":[],"type":"code_injection","year":"2026"},"n_packages":2,"n_references":3,"next":{"headline":"Handlebars.js has JavaScript Injection via AST Type Confusion by tampering @partial-block","id":"CVE-2026-33938"},"packages":[{"ecosystem":"npm","fixed":["4.7.9"],"introduced":["4.0.0"],"last_affected":[],"package":"handlebars","purl":null,"source":"GHSA-2w6w-674q-4c4q"},{"ecosystem":"npm","fixed":["4.7.9"],"introduced":["4.0.0"],"last_affected":[],"package":"handlebars","purl":"pkg:npm/handlebars","source":"GHSA-2w6w-674q-4c4q"}],"prev":{"headline":"python-ecdsa: Denial of Service via improper DER length validation in crafted private keys","id":"CVE-2026-33936"},"products":["handlebars.js"],"published":"2026-03-27","related":[{"cvss_score":8.3,"headline":"Handlebars.js has JavaScript Injection in CLI Precompiler via Unescaped Names and Options","id":"CVE-2026-33941","kev_date_added":null,"published":"2026-03-27"},{"cvss_score":8.1,"headline":"Handlebars.js has JavaScript Injection via AST Type Confusion by tampering @partial-block","id":"CVE-2026-33938","kev_date_added":null,"published":"2026-03-27"},{"cvss_score":8.1,"headline":"Handlebars.js has JavaScript Injection via AST Type Confusion when passing an object as dynamic partial","id":"CVE-2026-33940","kev_date_added":null,"published":"2026-03-27"},{"cvss_score":8.1,"headline":"Arbitrary Code Execution in Handlebars","id":"CVE-2019-20920","kev_date_added":null,"published":"2020-09-30"},{"cvss_score":7.5,"headline":"Handlebars.js has Denial of Service via Malformed Decorator Syntax in Template Compilation","id":"CVE-2026-33939","kev_date_added":null,"published":"2026-03-27"},{"cvss_score":7.5,"headline":"Regular Expression Denial of Service in Handlebars","id":"CVE-2019-20922","kev_date_added":null,"published":"2020-09-30"}],"sources":[{"class":"attribution","licence":"CVE Terms of Use (MITRE)","name":"CVE List","prefix":"CVE"},{"class":"attribution","licence":"CC BY 4.0","name":"GitHub Advisory Database","prefix":"GHSA"},{"class":"attribution","licence":"US public information, NVD API terms","name":"NVD"},{"class":"attribution","licence":"CWE Terms of Use","name":"CWE (MITRE)"},{"class":"attribution","licence":"FIRST CVSS licence","name":"CVSS (FIRST)"},{"class":"open","licence":"CC0","name":"PoC-in-GitHub"}],"ssvc":{"automatable":"yes","exploitation":"poc","technical_impact":"total"},"state":"PUBLISHED","updated":"2026-09-04","vendors":["handlebars-lang"]},"summary":"Attackers can inject arbitrary JavaScript into Handlebars templates via crafted AST objects, leading to remote code execution on the server.","url":"https://insights.sbomify.com/CVE-2026-33937/"}