{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-33938", "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa", "state": "PUBLISHED", "assignerShortName": "GitHub_M", "dateReserved": "2026-03-24T19:50:52.103Z", "datePublished": "2026-03-27T21:05:42.485Z", "dateUpdated": "2026-09-04T12:04:55.157Z" }, "containers": { "cna": { "title": "Handlebars.js has JavaScript Injection via AST Type Confusion by tampering @partial-block", "problemTypes": [ { "descriptions": [ { "cweId": "CWE-94", "lang": "en", "description": "CWE-94: Improper Control of Generation of Code ('Code Injection')", "type": "CWE" } ] }, { "descriptions": [ { "cweId": "CWE-843", "lang": "en", "description": "CWE-843: Access of Resource Using Incompatible Type ('Type Confusion')", "type": "CWE" } ] } ], "metrics": [ { "cvssV3_1": { "attackComplexity": "HIGH", "attackVector": "NETWORK", "availabilityImpact": "HIGH", "baseScore": 8.1, "baseSeverity": "HIGH", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "privilegesRequired": "NONE", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H", "version": "3.1" } } ], "references": [ { "name": "https://github.com/handlebars-lang/handlebars.js/security/advisories/GHSA-3mfm-83xf-c92r", "tags": [ "x_refsource_CONFIRM" ], "url": "https://github.com/handlebars-lang/handlebars.js/security/advisories/GHSA-3mfm-83xf-c92r" }, { "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": "2026-03-27T21:05:42.485Z" }, "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 `@partial-block` special variable is stored in the template data context and is reachable and mutable from within a template via helpers that accept arbitrary objects. When a helper overwrites `@partial-block` with a crafted Handlebars AST, a subsequent invocation of `{{> @partial-block}}` compiles and executes that AST, enabling arbitrary JavaScript execution on the server. Version 4.7.9 fixes the issue. Some workarounds are available. First, use the runtime-only build (`require('handlebars/runtime')`). The `compile()` method is absent, eliminating the vulnerable fallback path. Second, audit registered helpers for any that write arbitrary values to context objects. Helpers should treat context data as read-only. Third, avoid registering helpers from third-party packages (such as `handlebars-helpers`) in contexts where templates or context data can be influenced by untrusted input." } ], "source": { "advisory": "GHSA-3mfm-83xf-c92r", "discovery": "UNKNOWN" } }, "adp": [ { "references": [ { "url": "https://github.com/handlebars-lang/handlebars.js/security/advisories/GHSA-3mfm-83xf-c92r", "tags": [ "exploit" ] } ], "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-2026-33938" } } } ], "title": "CISA ADP Vulnrichment", "providerMetadata": { "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-04-01T03:55:42.796Z" } }, { "affected": [ { "collectionURL": "https://catalog.redhat.com/software/containers/", "cpes": [ 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"cluster-observability-operator/troubleshooting-panel-console-plugin-pf6-rhel9", "product": "Cluster Observability Operator 1.5.0", "vendor": "Red Hat", "versions": [ { "lessThan": "*", "status": "unaffected", "version": "1782839996", "versionType": "rpm" } ] }, { "collectionURL": "https://catalog.redhat.com/software/containers/", "cpes": [ "cpe:/a:redhat:openshift_devspaces:3.27::el9" ], "defaultStatus": "affected", "packageName": "devspaces/code-rhel9", "product": "Red Hat OpenShift Dev Spaces 3.27", "vendor": "Red Hat", "versions": [ { "lessThan": "*", "status": "unaffected", "version": "1776744110", "versionType": "rpm" } ] }, { "collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "cpes": [ "cpe:/a:redhat:cryostat:4" ], "defaultStatus": "unaffected", "packageName": "handlebars", "product": "Cryostat 4", "vendor": "Red Hat" }, { "collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "cpes": [ "cpe:/a:redhat:logging:5" ], 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"https://access.redhat.com/downloads/content/package-browser/", "cpes": [ "cpe:/a:redhat:openshift_devspaces:3" ], "defaultStatus": "unaffected", "packageName": "devspaces/dashboard-rhel9", "product": "Red Hat OpenShift Dev Spaces", "vendor": "Red Hat" }, { "collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "cpes": [ "cpe:/a:redhat:jboss_enterprise_bpms_platform:7" ], "defaultStatus": "unaffected", "packageName": "handlebars", "product": "Red Hat Process Automation 7", "vendor": "Red Hat" } ], "datePublic": "2026-03-27T21:05:42.485Z", "descriptions": [ { "lang": "en", "value": "A flaw was found in Handlebars. A remote attacker can exploit this vulnerability by manipulating the `@partial-block` special variable within the template data context. By overwriting `@partial-block` with a specially crafted Abstract Syntax Tree (AST) through a helper, a subsequent invocation of `{{> @partial-block}}` will compile and execute the malicious AST. This enables arbitrary JavaScript execution on the server, leading to potential compromise of the system." } ], "metrics": [ { "other": { "content": { "namespace": "https://access.redhat.com/security/updates/classification/", "value": "Important" }, "type": "Red Hat severity rating" } }, { "cvssV3_1": { "attackComplexity": "HIGH", "attackVector": "NETWORK", "availabilityImpact": "HIGH", "baseScore": 8.1, "baseSeverity": "HIGH", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "privilegesRequired": "NONE", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H", "version": "3.1" }, "format": "CVSS" } ], "problemTypes": [ { "descriptions": [ { "cweId": "CWE-917", "description": "Improper Neutralization of Special Elements used in an Expression Language Statement ('Expression Language Injection')", "lang": "en", "type": "CWE" } ] } ], "references": [ { "tags": [ "vdb-entry", "x_refsource_REDHAT" ], "url": "https://access.redhat.com/security/cve/CVE-2026-33938" }, { "name": "RHBZ#2452525", "tags": [ "issue-tracking", "x_refsource_REDHAT" ], "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2452525" }, { "tags": [ "x_sadp-csaf-vex" ], "url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-33938.json" }, { "tags": [ "vendor-advisory", "x_refsource_REDHAT" ], "url": "https://access.redhat.com/errata/RHSA-2026:34342" }, { "tags": [ "vendor-advisory", "x_refsource_REDHAT" ], "url": "https://access.redhat.com/errata/RHSA-2026:10175" } ], "solutions": [ { "lang": "en", "value": "RHSA-2026:34342: Cluster Observability Operator 1.5.0" }, { "lang": "en", "value": "RHSA-2026:10175: Red Hat OpenShift Dev Spaces 3.27" } ], "timeline": [ { "lang": "en", "time": "2026-03-27T22:02:58.504Z", "value": "Reported to Red Hat." }, { "lang": "en", "time": "2026-03-27T21:05:42.485Z", "value": "Made public." } ], "title": "handlebars: Handlebars: Arbitrary code execution via @partial-block overwrite", "workarounds": [ { "lang": "en", "value": "Applications using Handlebars should implement the runtime-only build (`require('handlebars/runtime')`) to prevent exploitation, as this build lacks the vulnerable `compile()` method. Additionally, review all registered helpers to ensure they do not write arbitrary values to context objects, and avoid using third-party helpers in contexts exposed to untrusted input." } ], "x_adpType": "supplier", "x_generator": { "engine": "sadp-cli 1.0.0" }, "providerMetadata": { "orgId": "0b0ca135-0b70-47e7-9f44-1890c2a1c46c", "shortName": "redhat-SADP", "dateUpdated": "2026-09-04T12:04:55.157Z" } } ] } }