{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-33941", "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa", "state": "PUBLISHED", "assignerShortName": "GitHub_M", "dateReserved": "2026-03-24T19:50:52.104Z", "datePublished": "2026-03-27T21:13:15.437Z", "dateUpdated": "2026-04-01T03:55:37.742Z"}, "containers": {"cna": {"title": "Handlebars.js has JavaScript Injection in CLI Precompiler via Unescaped Names and Options", "problemTypes": [{"descriptions": [{"cweId": "CWE-79", "lang": "en", "description": "CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')", "type": "CWE"}]}, {"descriptions": [{"cweId": "CWE-94", "lang": "en", "description": "CWE-94: Improper Control of Generation of Code ('Code Injection')", "type": "CWE"}]}, {"descriptions": [{"cweId": "CWE-116", "lang": "en", "description": "CWE-116: Improper Encoding or Escaping of Output", "type": "CWE"}]}], "metrics": [{"cvssV3_1": {"attackComplexity": "LOW", "attackVector": "LOCAL", "availabilityImpact": "HIGH", "baseScore": 8.3, "baseSeverity": "HIGH", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "privilegesRequired": "LOW", "scope": "CHANGED", "userInteraction": "REQUIRED", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:H", "version": "3.1"}}], "references": [{"name": "https://github.com/handlebars-lang/handlebars.js/security/advisories/GHSA-xjpj-3mr7-gcpf", "tags": ["x_refsource_CONFIRM"], "url": "https://github.com/handlebars-lang/handlebars.js/security/advisories/GHSA-xjpj-3mr7-gcpf"}, {"name": "https://github.com/handlebars-lang/handlebars.js/commit/68d8df5a88e0a26fe9e6084c5c6aaebe67b07da2", "tags": ["x_refsource_MISC"], "url": "https://github.com/handlebars-lang/handlebars.js/commit/68d8df5a88e0a26fe9e6084c5c6aaebe67b07da2"}, {"name": "https://github.com/handlebars-lang/handlebars.js/releases/tag/v4.7.9", "tags": ["x_refsource_MISC"], "url": "https://github.com/handlebars-lang/handlebars.js/releases/tag/v4.7.9"}], "affected": [{"vendor": "handlebars-lang", "product": "handlebars.js", "versions": [{"version": ">= 4.0.0, < 4.7.9", "status": "affected"}]}], "providerMetadata": {"orgId": "a0819718-46f1-4df5-94e2-005712e83aaa", "shortName": "GitHub_M", "dateUpdated": "2026-03-27T21:13:15.437Z"}, "descriptions": [{"lang": "en", "value": "Handlebars provides the power necessary to let users build semantic templates. In versions 4.0.0 through 4.7.8, the Handlebars CLI precompiler (`bin/handlebars` / `lib/precompiler.js`) concatenates user-controlled strings \u2014 template file names and several CLI options \u2014 directly into the JavaScript it emits, without any escaping or sanitization. An attacker who can influence template filenames or CLI arguments can inject arbitrary JavaScript that executes when the generated bundle is loaded in Node.js or a browser. Version 4.7.9 fixes the issue. Some workarounds are available. First, validate all CLI inputs before invoking the precompiler. Reject filenames and option values that contain characters with JavaScript string-escaping significance (`\"`, `'`, `;`, etc.). Second, use a fixed, trusted namespace string passed via a configuration file rather than command-line arguments in automated pipelines. Third, run the precompiler in a sandboxed environment (container with no write access to sensitive paths) to limit the impact of successful exploitation. Fourth, audit template filenames in any repository or package that is consumed by an automated build pipeline."}], "source": {"advisory": "GHSA-xjpj-3mr7-gcpf", "discovery": "UNKNOWN"}}, "adp": [{"metrics": [{"other": {"type": "ssvc", "content": {"timestamp": "2026-03-31T00:00:00+00:00", "options": [{"Exploitation": "poc"}, {"Automatable": "no"}, {"Technical Impact": "total"}], "role": "CISA Coordinator", "version": "2.0.3", "id": "CVE-2026-33941"}}}], "title": "CISA ADP Vulnrichment", "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-04-01T03:55:37.742Z"}}]}}

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{"configurations": [{"nodes": [{"cpeMatch": [{"criteria": "cpe:2.3:a:handlebarsjs:handlebars:*:*:*:*:*:node.js:*:*", "matchCriteriaId": "A9D1F9A7-8359-4C3F-9932-4A085094F388", "versionEndExcluding": "4.7.9", "versionStartIncluding": "4.0.0", "vulnerable": true}], "negate": false, "operator": "OR"}]}], "cveTags": [], "descriptions": [{"lang": "en", "value": "Handlebars provides the power necessary to let users build semantic templates. In versions 4.0.0 through 4.7.8, the Handlebars CLI precompiler (`bin/handlebars` / `lib/precompiler.js`) concatenates user-controlled strings \u2014 template file names and several CLI options \u2014 directly into the JavaScript it emits, without any escaping or sanitization. An attacker who can influence template filenames or CLI arguments can inject arbitrary JavaScript that executes when the generated bundle is loaded in Node.js or a browser. Version 4.7.9 fixes the issue. Some workarounds are available. First, validate all CLI inputs before invoking the precompiler. Reject filenames and option values that contain characters with JavaScript string-escaping significance (`\"`, `'`, `;`, etc.). Second, use a fixed, trusted namespace string passed via a configuration file rather than command-line arguments in automated pipelines. Third, run the precompiler in a sandboxed environment (container with no write access to sensitive paths) to limit the impact of successful exploitation. Fourth, audit template filenames in any repository or package that is consumed by an automated build pipeline."}], "id": "CVE-2026-33941", "lastModified": "2026-03-31T17:53:18.770", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "LOCAL", "availabilityImpact": "HIGH", "baseScore": 8.2, "baseSeverity": "HIGH", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "privilegesRequired": "LOW", "scope": "CHANGED", "userInteraction": "REQUIRED", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:H", "version": "3.1"}, "exploitabilityScore": 1.5, "impactScore": 6.0, "source": "security-advisories@github.com", "type": "Secondary"}, {"cvssData": {"attackComplexity": "LOW", "attackVector": "LOCAL", "availabilityImpact": "HIGH", "baseScore": 8.2, "baseSeverity": "HIGH", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "privilegesRequired": "LOW", "scope": "CHANGED", "userInteraction": "REQUIRED", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:H", "version": "3.1"}, "exploitabilityScore": 1.5, "impactScore": 6.0, "source": "nvd@nist.gov", "type": "Primary"}]}, "published": "2026-03-27T22:16:21.203", "references": [{"source": "security-advisories@github.com", "tags": ["Patch"], "url": "https://github.com/handlebars-lang/handlebars.js/commit/68d8df5a88e0a26fe9e6084c5c6aaebe67b07da2"}, {"source": "security-advisories@github.com", "tags": ["Release Notes"], "url": "https://github.com/handlebars-lang/handlebars.js/releases/tag/v4.7.9"}, {"source": "security-advisories@github.com", "tags": ["Exploit", "Vendor Advisory"], "url": "https://github.com/handlebars-lang/handlebars.js/security/advisories/GHSA-xjpj-3mr7-gcpf"}], "sourceIdentifier": "security-advisories@github.com", "vulnStatus": "Analyzed", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-79"}, {"lang": "en", "value": "CWE-94"}, {"lang": "en", "value": "CWE-116"}], "source": "security-advisories@github.com", "type": "Primary"}]}

{"bugzilla": {"description": "handlebars.js: Handlebars: Arbitrary code execution via CLI precompiler input sanitization flaw", "id": "2452524", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2452524"}, "csaw": false, "cvss3": {"cvss3_base_score": "8.2", "cvss3_scoring_vector": "CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:H", "status": "draft"}, "cwe": "CWE-94", "details": ["A flaw was found in Handlebars. The Handlebars command-line interface (CLI) precompiler concatenates user-controlled strings, such as template file names and CLI options, directly into the generated JavaScript without proper escaping or sanitization. An attacker capable of influencing these inputs can inject arbitrary JavaScript code. This can lead to arbitrary code execution when the generated JavaScript bundle is loaded in a Node.js environment or a web browser."], "mitigation": {"lang": "en:us", "value": "To mitigate this issue, ensure all inputs to the Handlebars CLI precompiler are thoroughly validated, rejecting characters with JavaScript string-escaping significance (e.g., \\\" , \\' , ;). For automated build pipelines, configure a fixed and trusted namespace string via a configuration file rather than passing it through command-line arguments. Additionally, consider running the precompiler within a sandboxed environment, such as a container with restricted write access, to limit the potential impact of successful exploitation."}, "name": "CVE-2026-33941", "package_state": [{"cpe": "cpe:/a:redhat:cryostat:4", "fix_state": "Affected", "package_name": "handlebars", "product_name": "Cryostat 4"}, {"cpe": "cpe:/a:redhat:logging:5", "fix_state": "Affected", "package_name": "openshift-logging/elasticsearch6-rhel9", "product_name": "Logging Subsystem for Red Hat OpenShift"}, {"cpe": "cpe:/a:redhat:logging:5", "fix_state": "Affected", "package_name": "openshift-logging/elasticsearch-operator-bundle", "product_name": "Logging Subsystem for Red Hat OpenShift"}, {"cpe": "cpe:/a:redhat:logging:5", "fix_state": "Affected", "package_name": "openshift-logging/elasticsearch-proxy-rhel9", "product_name": "Logging Subsystem for Red Hat OpenShift"}, {"cpe": "cpe:/a:redhat:logging:5", "fix_state": "Affected", "package_name": "openshift-logging/elasticsearch-rhel9-operator", "product_name": "Logging Subsystem for Red Hat OpenShift"}, {"cpe": "cpe:/a:redhat:logging:5", "fix_state": "Affected", "package_name": "openshift-logging/kibana6-rhel8", "product_name": "Logging Subsystem for Red Hat OpenShift"}, {"cpe": "cpe:/a:redhat:logging:5", "fix_state": "Affected", "package_name": "openshift-logging/logging-curator5-rhel9", "product_name": "Logging Subsystem for Red Hat OpenShift"}, {"cpe": "cpe:/a:redhat:jboss_data_grid:8", "fix_state": "Affected", "package_name": "handlebars", "product_name": "Red Hat Data Grid 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:10", "fix_state": "Affected", "package_name": "firefox", "product_name": "Red Hat Enterprise Linux 10"}, {"cpe": "cpe:/o:redhat:enterprise_linux:10", "fix_state": "Affected", "package_name": "thunderbird", "product_name": "Red Hat Enterprise Linux 10"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Affected", "package_name": "firefox", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Affected", "package_name": "389-ds:1.4/389-ds-base", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Affected", "package_name": "firefox", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Affected", "package_name": "grafana", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Affected", "package_name": "mozjs60", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Affected", "package_name": "thunderbird", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Affected", "package_name": "firefox", "product_name": "Red Hat Enterprise Linux 9"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Affected", "package_name": "thunderbird", "product_name": "Red Hat Enterprise Linux 9"}, {"cpe": "cpe:/a:redhat:openshift_ai", "fix_state": "Affected", "package_name": "rhoai/odh-workbench-codeserver-datascience-cpu-py312-rhel9", "product_name": "Red Hat OpenShift AI (RHOAI)"}, {"cpe": "cpe:/a:redhat:openshift_devspaces:3", "fix_state": "Affected", "package_name": "devspaces/code-rhel9", "product_name": "Red Hat OpenShift Dev Spaces"}, {"cpe": "cpe:/a:redhat:jboss_enterprise_bpms_platform:7", "fix_state": "Affected", "package_name": "handlebars", "product_name": "Red Hat Process Automation 7"}], "public_date": "2026-03-27T21:13:15Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2026-33941\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-33941\nhttps://github.com/handlebars-lang/handlebars.js/commit/68d8df5a88e0a26fe9e6084c5c6aaebe67b07da2\nhttps://github.com/handlebars-lang/handlebars.js/releases/tag/v4.7.9\nhttps://github.com/handlebars-lang/handlebars.js/security/advisories/GHSA-xjpj-3mr7-gcpf"], "statement": "Important: This flaw in Handlebars allows arbitrary code execution when the CLI precompiler processes untrusted inputs. An attacker who can influence template filenames or command-line arguments can inject malicious JavaScript, which executes when the generated bundle is loaded. Red Hat products utilizing the Handlebars CLI precompiler in environments where untrusted inputs are processed may be affected.", "threat_severity": "Important"}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[4.0.0,4.7.9)"}}], "enrichment": {"confidence": 81.0, "confidence_source": "matching", "scores": [{"score": 81.0, "source": "matching"}]}, "original": {"product": "handlebars.js", "source": "cna", "vendor": "handlebars-lang"}, "product": "handlebars", "vendor": "handlebarsjs"}], "analysis": {"en": {"generated_at": "2026-03-31T19:41:33.103884+00:00", "value": {"mitigation_remediation": ["Upgrade Handlebars.js to version 4.7.9 or later.", "Validate all CLI input before invoking the precompiler.", "Reject filenames or option values that contain characters with JavaScript string\u2011escaping significance such as \"', ;, and backslashes.", "Configure a trusted namespace string via an external configuration file instead of passing it on the command line.", "Execute the precompiler in a sandboxed container without write access to sensitive paths.", "Audit template filenames in repositories or packages that are consumed by automated build pipelines."], "summary": {"action": "Update Immediately", "impact": "JavaScript Injection via the Handlebars CLI precompiler"}, "threat_synthesis": {"affected_systems": "Versions of Handlebars.js from 4.0.0 up to and including 4.7.8 are affected when the CLI precompiler is used. The problem is tied to the CLI tool bin/handlebars and its underlying precompiler script. The issue affects all platforms where Node.js is used to compile templates, as well as browsers that load the generated bundle. Handlebars\u2011lang:handlebars.js is the vendor, and the Fix appears in release 4.7.9.", "description_and_impact": "The vulnerability allows an attacker who can influence Handlebars template filenames or command\u2011line options to inject arbitrary JavaScript into the bundle generated by the CLI precompiler. The undersanitized concatenation of user\u2011controlled strings into the emitted code creates a classic code\u2011injection flaw that can execute when the bundle is loaded in Node.js or a browser. This enables remote code execution and compromises confidentiality, integrity, and availability of the runtime environment.", "risk_and_exploitability": "The CVSS score of 8.3 indicates a high\u2011severity vulnerability. EPSS is reported as below 1\u202f% and the issue is not listed in CISA\u2019s KEV catalog, which suggests limited automated exploitation data at present. The likely attack vector derives from a user running the Handlebars CLI with crafted template filenames or options, a scenario common in automated build pipelines or local development. If an attacker can control the precompile step, they can inject executable JavaScript, which then runs with the privileges of the process loading the bundle."}}}}, "created": "2026-03-29T20:29:47.912814+00:00", "updated": "2026-03-31T20:00:38.942980+00:00", "vendors": ["handlebarsjs", "handlebarsjs$PRODUCT$handlebars"]}