FKIE_CVE-2026-33940
Vulnerability from fkie_nvd - Published: 2026-03-27 22:16 - Updated: 2026-09-04 13:19
Severity
8.1 (High) - CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
8.1 (High) - CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
8.1 (High) - CVSS:3.1/
Summary
Handlebars provides the power necessary to let users build semantic templates. In versions 4.0.0 through 4.7.8, a crafted object placed in the template context can bypass all conditional guards in `resolvePartial()` and cause `invokePartial()` to return `undefined`. The Handlebars runtime then treats the unresolved partial as a source that needs to be compiled, passing the crafted object to `env.compile()`. Because the object is a valid Handlebars AST containing injected code, the generated JavaScript executes arbitrary commands on the server. The attack requires the adversary to control a value that can be returned by a dynamic partial lookup. Version 4.7.9 fixes the issue. Some workarounds are available. First, use the runtime-only build (`require('handlebars/runtime')`). Without `compile()`, the fallback compilation path in `invokePartial` is unreachable. Second, sanitize context data before rendering: Ensure no value in the context is a non-primitive object that could be passed to a dynamic partial. Third, avoid dynamic partial lookups (`{{> (lookup ...)}}`) when context data is user-controlled.
References
Impacted products
| Vendor | Product | Version | |
|---|---|---|---|
| handlebarsjs | handlebars | * |
{
"affected": [
{
"affectedData": [
{
"product": "handlebars.js",
"vendor": "handlebars-lang",
"versions": [
{
"status": "affected",
"version": "\u003e= 4.0.0, \u003c 4.7.9"
}
]
}
],
"source": "security-advisories@github.com"
},
{
"affectedData": [
{
"collectionURL": "https://catalog.redhat.com/software/containers/",
"cpes": [
"cpe:/a:redhat:cluster_observability_operator:1.5::el9"
],
"defaultStatus": "affected",
"packageName": "cluster-observability-operator/logging-console-plugin-pf4-rhel9",
"product": "Cluster Observability Operator 1.5.0",
"vendor": "Red Hat",
"versions": [
{
"lessThan": "*",
"status": "unaffected",
"version": "1782839279",
"versionType": "rpm"
}
]
},
{
"collectionURL": "https://catalog.redhat.com/software/containers/",
"cpes": [
"cpe:/a:redhat:cluster_observability_operator:1.5::el9"
],
"defaultStatus": "affected",
"packageName": "cluster-observability-operator/logging-console-plugin-pf5-rhel9",
"product": "Cluster Observability Operator 1.5.0",
"vendor": "Red Hat",
"versions": [
{
"lessThan": "*",
"status": "unaffected",
"version": "1782840539",
"versionType": "rpm"
}
]
},
{
"collectionURL": "https://catalog.redhat.com/software/containers/",
"cpes": [
"cpe:/a:redhat:cluster_observability_operator:1.5::el9"
],
"defaultStatus": "affected",
"packageName": "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"
],
"defaultStatus": "affected",
"packageName": "openshift-logging/elasticsearch6-rhel9",
"product": "Logging Subsystem for Red Hat OpenShift",
"vendor": "Red Hat"
},
{
"collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
"cpes": [
"cpe:/a:redhat:logging:5"
],
"defaultStatus": "affected",
"packageName": "openshift-logging/elasticsearch-operator-bundle",
"product": "Logging Subsystem for Red Hat OpenShift",
"vendor": "Red Hat"
},
{
"collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
"cpes": [
"cpe:/a:redhat:logging:5"
],
"defaultStatus": "affected",
"packageName": "openshift-logging/elasticsearch-proxy-rhel9",
"product": "Logging Subsystem for Red Hat OpenShift",
"vendor": "Red Hat"
},
{
"collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
"cpes": [
"cpe:/a:redhat:logging:5"
],
"defaultStatus": "affected",
"packageName": "openshift-logging/elasticsearch-rhel9-operator",
"product": "Logging Subsystem for Red Hat OpenShift",
"vendor": "Red Hat"
},
{
"collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
"cpes": [
"cpe:/a:redhat:logging:5"
],
"defaultStatus": "affected",
"packageName": "openshift-logging/kibana6-rhel8",
"product": "Logging Subsystem for Red Hat OpenShift",
"vendor": "Red Hat"
},
{
"collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
"cpes": [
"cpe:/a:redhat:logging:5"
],
"defaultStatus": "affected",
"packageName": "openshift-logging/logging-curator5-rhel9",
"product": "Logging Subsystem for Red Hat OpenShift",
"vendor": "Red Hat"
},
{
"collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
"cpes": [
"cpe:/a:redhat:jboss_data_grid:8"
],
"defaultStatus": "unaffected",
"packageName": "handlebars",
"product": "Red Hat Data Grid 8",
"vendor": "Red Hat"
},
{
"collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
"cpes": [
"cpe:/o:redhat:enterprise_linux:10"
],
"defaultStatus": "unaffected",
"packageName": "firefox",
"product": "Red Hat Enterprise Linux 10",
"vendor": "Red Hat"
},
{
"collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
"cpes": [
"cpe:/o:redhat:enterprise_linux:10"
],
"defaultStatus": "affected",
"packageName": "thunderbird",
"product": "Red Hat Enterprise Linux 10",
"vendor": "Red Hat"
},
{
"collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
"cpes": [
"cpe:/o:redhat:enterprise_linux:7"
],
"defaultStatus": "unaffected",
"packageName": "firefox",
"product": "Red Hat Enterprise Linux 7",
"vendor": "Red Hat"
},
{
"collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
"cpes": [
"cpe:/o:redhat:enterprise_linux:8"
],
"defaultStatus": "affected",
"packageName": "389-ds:1.4/389-ds-base",
"product": "Red Hat Enterprise Linux 8",
"vendor": "Red Hat"
},
{
"collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
"cpes": [
"cpe:/o:redhat:enterprise_linux:8"
],
"defaultStatus": "unaffected",
"packageName": "firefox",
"product": "Red Hat Enterprise Linux 8",
"vendor": "Red Hat"
},
{
"collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
"cpes": [
"cpe:/o:redhat:enterprise_linux:8"
],
"defaultStatus": "unaffected",
"packageName": "grafana",
"product": "Red Hat Enterprise Linux 8",
"vendor": "Red Hat"
},
{
"collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
"cpes": [
"cpe:/o:redhat:enterprise_linux:8"
],
"defaultStatus": "unaffected",
"packageName": "mozjs60",
"product": "Red Hat Enterprise Linux 8",
"vendor": "Red Hat"
},
{
"collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
"cpes": [
"cpe:/o:redhat:enterprise_linux:8"
],
"defaultStatus": "unaffected",
"packageName": "thunderbird",
"product": "Red Hat Enterprise Linux 8",
"vendor": "Red Hat"
},
{
"collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
"cpes": [
"cpe:/o:redhat:enterprise_linux:9"
],
"defaultStatus": "affected",
"packageName": "firefox",
"product": "Red Hat Enterprise Linux 9",
"vendor": "Red Hat"
},
{
"collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
"cpes": [
"cpe:/o:redhat:enterprise_linux:9"
],
"defaultStatus": "unaffected",
"packageName": "thunderbird",
"product": "Red Hat Enterprise Linux 9",
"vendor": "Red Hat"
},
{
"collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
"cpes": [
"cpe:/a:redhat:openshift_ai"
],
"defaultStatus": "unaffected",
"packageName": "rhoai/odh-workbench-codeserver-datascience-cpu-py312-rhel9",
"product": "Red Hat OpenShift AI (RHOAI)",
"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"
}
],
"source": "0b0ca135-0b70-47e7-9f44-1890c2a1c46c"
}
],
"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, a crafted object placed in the template context can bypass all conditional guards in `resolvePartial()` and cause `invokePartial()` to return `undefined`. The Handlebars runtime then treats the unresolved partial as a source that needs to be compiled, passing the crafted object to `env.compile()`. Because the object is a valid Handlebars AST containing injected code, the generated JavaScript executes arbitrary commands on the server. The attack requires the adversary to control a value that can be returned by a dynamic partial lookup. Version 4.7.9 fixes the issue. Some workarounds are available. First, use the runtime-only build (`require(\u0027handlebars/runtime\u0027)`). Without `compile()`, the fallback compilation path in `invokePartial` is unreachable. Second, sanitize context data before rendering: Ensure no value in the context is a non-primitive object that could be passed to a dynamic partial. Third, avoid dynamic partial lookups (`{{\u003e (lookup ...)}}`) when context data is user-controlled."
}
],
"id": "CVE-2026-33940",
"lastModified": "2026-09-04T13:19:26.440",
"metrics": {
"cvssMetricV31": [
{
"cvssData": {
"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"
},
"exploitabilityScore": 2.2,
"impactScore": 5.9,
"source": "security-advisories@github.com",
"type": "Secondary"
},
{
"cvssData": {
"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"
},
"exploitabilityScore": 2.2,
"impactScore": 5.9,
"source": "0b0ca135-0b70-47e7-9f44-1890c2a1c46c",
"type": "Secondary"
}
],
"ssvcV203": [
{
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"ssvcData": {
"id": "CVE-2026-33940",
"options": [
{
"exploitation": "poc"
},
{
"automatable": "no"
},
{
"technicalImpact": "total"
}
],
"role": "CISA Coordinator",
"timestamp": "2026-03-31T00:00:00+00:00",
"version": "2.0.3"
}
}
]
},
"published": "2026-03-27T22:16:21.030",
"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-xhpv-hc6g-r9c6"
},
{
"source": "0b0ca135-0b70-47e7-9f44-1890c2a1c46c",
"url": "https://access.redhat.com/errata/RHSA-2026:10175"
},
{
"source": "0b0ca135-0b70-47e7-9f44-1890c2a1c46c",
"url": "https://access.redhat.com/errata/RHSA-2026:34342"
},
{
"source": "0b0ca135-0b70-47e7-9f44-1890c2a1c46c",
"url": "https://access.redhat.com/security/cve/CVE-2026-33940"
},
{
"source": "0b0ca135-0b70-47e7-9f44-1890c2a1c46c",
"url": "https://bugzilla.redhat.com/show_bug.cgi?id=2452521"
},
{
"source": "0b0ca135-0b70-47e7-9f44-1890c2a1c46c",
"url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-33940.json"
}
],
"sourceIdentifier": "security-advisories@github.com",
"vulnStatus": "Modified",
"weaknesses": [
{
"description": [
{
"lang": "en",
"value": "CWE-94"
},
{
"lang": "en",
"value": "CWE-843"
}
],
"source": "security-advisories@github.com",
"type": "Secondary"
},
{
"description": [
{
"lang": "en",
"value": "CWE-94"
}
],
"source": "0b0ca135-0b70-47e7-9f44-1890c2a1c46c",
"type": "Secondary"
}
]
}
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Experimental. This forecast is provided for visualization only and may change without notice. Do not use it for operational decisions.
Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.
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The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the
vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base
model, served locally by ML-Gateway.
They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.
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Related by attack behaviour
Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.
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