CVE-2026-33937

Estado: ModificadaCrítica (9.8)—

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.

Leer descripción completaMostrar menos

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.

CVSS

Versión: 3.1
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Puntuación base: 9.8

Probabilidad de explotación (EPSS)

Probabilidad de explotación en los próximos 30 días: 1.74%
Percentil entre todas las CVEs puntuadas: 77
Fecha de la puntuación: 6/10/2026

EPSS (Exploit Prediction Scoring System, de FIRST) estima la probabilidad de que una vulnerabilidad sea explotada en 30 días. Complementa a CVSS (impacto) y a CISA KEV (explotación confirmada).

🎯 Técnicas ATT&CK

Cómo se explota esta vulnerabilidad y qué consigue el atacante, en el lenguaje de MITRE ATT&CK.

ExplotaciónT1190 Exploit Public-Facing Applicationinitial access90 %
Impacto principalT1059 Command and Scripting Interpreterexecution95 %

Vulnerabilidad de inyección de código (CWE-94) en API web accesible sin autenticación. El atacante suministra un AST malicioso a Handlebars.compile() para ejecutar JavaScript arbitrario en el servidor, resultando en RCE.

Inferido por nuestro agente de análisis a partir de la descripción oficial, el vector CVSS y la CWE, y comprobado por un supervisor. Puede contener errores.

🛡️ Mitigaciones ATT&CK que cubren estas técnicas

Privileged Account Management Vulnerability Scanning Restrict Web-Based Content Network Segmentation Limit Software Installation Limit Access to Resource Over Network

Tecnologías afectadas (1)

Handlebarsjs — Handlebars

CWE

CWE-94, CWE-843
CWE-94

Referencias

JSON original (NVD)

Mostrar

{
  "id": "CVE-2026-33937",
  "cveTags": [],
  "metrics": {
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "id": "CVE-2026-33937",
          "role": "CISA Coordinator",
          "options": [
            {
              "exploitation": "poc"
            },
            {
              "automatable": "yes"
            },
            {
              "technicalImpact": "total"
            }
          ],
          "version": "2.0.3",
          "timestamp": "2026-03-31T00:00:00+00:00"
        }
      }
    ],
    "cvssMetricV31": [
      {
        "type": "Secondary",
        "source": "security-advisories@github.com",
        "cvssData": {
          "scope": "UNCHANGED",
          "version": "3.1",
          "baseScore": 9.8,
          "attackVector": "NETWORK",
          "baseSeverity": "CRITICAL",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
          "integrityImpact": "HIGH",
          "userInteraction": "NONE",
          "attackComplexity": "LOW",
          "availabilityImpact": "HIGH",
          "privilegesRequired": "NONE",
          "confidentialityImpact": "HIGH"
        },
        "impactScore": 5.9,
        "exploitabilityScore": 3.9
      },
      {
        "type": "Secondary",
        "source": "0b0ca135-0b70-47e7-9f44-1890c2a1c46c",
        "cvssData": {
          "scope": "UNCHANGED",
          "version": "3.1",
          "baseScore": 9.8,
          "attackVector": "NETWORK",
          "baseSeverity": "CRITICAL",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
          "integrityImpact": "HIGH",
          "userInteraction": "NONE",
          "attackComplexity": "LOW",
          "availabilityImpact": "HIGH",
          "privilegesRequired": "NONE",
          "confidentialityImpact": "HIGH"
        },
        "impactScore": 5.9,
        "exploitabilityScore": 3.9
      }
    ]
  },
  "affected": [
    {
      "source": "security-advisories@github.com",
      "affectedData": [
        {
          "vendor": "handlebars-lang",
          "product": "handlebars.js",
          "versions": [
            {
              "status": "affected",
              "version": ">= 4.0.0, < 4.7.9"
            }
          ]
        }
      ]
    },
    {
      "source": "0b0ca135-0b70-47e7-9f44-1890c2a1c46c",
      "affectedData": [
        {
          "cpes": [
            "cpe:/a:redhat:cluster_observability_operator:1.5::el9"
          ],
          "vendor": "Red Hat",
          "product": "Cluster Observability Operator 1.5.0",
          "versions": [
            {
              "status": "unaffected",
              "version": "1782839279",
              "lessThan": "*",
              "versionType": "rpm"
            }
          ],
          "packageName": "cluster-observability-operator/logging-console-plugin-pf4-rhel9",
          "collectionURL": "https://catalog.redhat.com/software/containers/",
          "defaultStatus": "affected"
        },
        {
          "cpes": [
            "cpe:/a:redhat:cluster_observability_operator:1.5::el9"
          ],
          "vendor": "Red Hat",
          "product": "Cluster Observability Operator 1.5.0",
          "versions": [
            {
              "status": "unaffected",
              "version": "1782840539",
              "lessThan": "*",
              "versionType": "rpm"
            }
          ],
          "packageName": "cluster-observability-operator/logging-console-plugin-pf5-rhel9",
          "collectionURL": "https://catalog.redhat.com/software/containers/",
          "defaultStatus": "affected"
        },
        {
          "cpes": [
            "cpe:/a:redhat:cluster_observability_operator:1.5::el9"
          ],
          "vendor": "Red Hat",
          "product": "Cluster Observability Operator 1.5.0",
          "versions": [
            {
              "status": "unaffected",
              "version": "1782839996",
              "lessThan": "*",
              "versionType": "rpm"
            }
          ],
          "packageName": "cluster-observability-operator/troubleshooting-panel-console-plugin-pf6-rhel9",
          "collectionURL": "https://catalog.redhat.com/software/containers/",
          "defaultStatus": "affected"
        },
        {
          "cpes": [
            "cpe:/a:redhat:openshift_devspaces:3.27::el9"
          ],
          "vendor": "Red Hat",
          "product": "Red Hat OpenShift Dev Spaces 3.27",
          "versions": [
            {
              "status": "unaffected",
              "version": "1776744110",
              "lessThan": "*",
              "versionType": "rpm"
            }
          ],
          "packageName": "devspaces/code-rhel9",
          "collectionURL": "https://catalog.redhat.com/software/containers/",
          "defaultStatus": "affected"
        },
        {
          "cpes": [
            "cpe:/a:redhat:cryostat:4"
          ],
          "vendor": "Red Hat",
          "product": "Cryostat 4",
          "packageName": "handlebars",
          "collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
          "defaultStatus": "unaffected"
        },
        {
          "cpes": [
            "cpe:/a:redhat:logging:5"
          ],
          "vendor": "Red Hat",
          "product": "Logging Subsystem for Red Hat OpenShift",
          "packageName": "openshift-logging/elasticsearch6-rhel9",
          "collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
          "defaultStatus": "affected"
        },
        {
          "cpes": [
            "cpe:/a:redhat:logging:5"
          ],
          "vendor": "Red Hat",
          "product": "Logging Subsystem for Red Hat OpenShift",
          "packageName": "openshift-logging/elasticsearch-operator-bundle",
          "collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
          "defaultStatus": "affected"
        },
        {
          "cpes": [
            "cpe:/a:redhat:logging:5"
          ],
          "vendor": "Red Hat",
          "product": "Logging Subsystem for Red Hat OpenShift",
          "packageName": "openshift-logging/elasticsearch-proxy-rhel9",
          "collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
          "defaultStatus": "affected"
        },
        {
          "cpes": [
            "cpe:/a:redhat:logging:5"
          ],
          "vendor": "Red Hat",
          "product": "Logging Subsystem for Red Hat OpenShift",
          "packageName": "openshift-logging/elasticsearch-rhel9-operator",
          "collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
          "defaultStatus": "affected"
        },
        {
          "cpes": [
            "cpe:/a:redhat:logging:5"
          ],
          "vendor": "Red Hat",
          "product": "Logging Subsystem for Red Hat OpenShift",
          "packageName": "openshift-logging/kibana6-rhel8",
          "collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
          "defaultStatus": "affected"
        },
        {
          "cpes": [
            "cpe:/a:redhat:logging:5"
          ],
          "vendor": "Red Hat",
          "product": "Logging Subsystem for Red Hat OpenShift",
          "packageName": "openshift-logging/logging-curator5-rhel9",
          "collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
          "defaultStatus": "affected"
        },
        {
          "cpes": [
            "cpe:/a:redhat:jboss_data_grid:8"
          ],
          "vendor": "Red Hat",
          "product": "Red Hat Data Grid 8",
          "packageName": "handlebars",
          "collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
          "defaultStatus": "unaffected"
        },
        {
          "cpes": [
            "cpe:/a:redhat:rhdh:1"
          ],
          "vendor": "Red Hat",
          "product": "Red Hat Developer Hub",
          "packageName": "rhdh/rhdh-hub-rhel9",
          "collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
          "defaultStatus": "affected"
        },
        {
          "cpes": [
            "cpe:/o:redhat:enterprise_linux:10"
          ],
          "vendor": "Red Hat",
          "product": "Red Hat Enterprise Linux 10",
          "packageName": "firefox",
          "collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
          "defaultStatus": "unaffected"
        },
        {
          "cpes": [
            "cpe:/o:redhat:enterprise_linux:10"
          ],
          "vendor": "Red Hat",
          "product": "Red Hat Enterprise Linux 10",
          "packageName": "thunderbird",
          "collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
          "defaultStatus": "affected"
        },
        {
          "cpes": [
            "cpe:/o:redhat:enterprise_linux:7"
          ],
          "vendor": "Red Hat",
          "product": "Red Hat Enterprise Linux 7",
          "packageName": "firefox",
          "collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
          "defaultStatus": "unaffected"
        },
        {
          "cpes": [
            "cpe:/o:redhat:enterprise_linux:8"
          ],
          "vendor": "Red Hat",
          "product": "Red Hat Enterprise Linux 8",
          "packageName": "389-ds:1.4/389-ds-base",
          "collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
          "defaultStatus": "affected"
        },
        {
          "cpes": [
            "cpe:/o:redhat:enterprise_linux:8"
          ],
          "vendor": "Red Hat",
          "product": "Red Hat Enterprise Linux 8",
          "packageName": "firefox",
          "collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
          "defaultStatus": "unaffected"
        },
        {
          "cpes": [
            "cpe:/o:redhat:enterprise_linux:8"
          ],
          "vendor": "Red Hat",
          "product": "Red Hat Enterprise Linux 8",
          "packageName": "grafana",
          "collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
          "defaultStatus": "unaffected"
        },
        {
          "cpes": [
            "cpe:/o:redhat:enterprise_linux:8"
          ],
          "vendor": "Red Hat",
          "product": "Red Hat Enterprise Linux 8",
          "packageName": "mozjs60",
          "collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
          "defaultStatus": "unaffected"
        },
        {
          "cpes": [
            "cpe:/o:redhat:enterprise_linux:8"
          ],
          "vendor": "Red Hat",
          "product": "Red Hat Enterprise Linux 8",
          "packageName": "thunderbird",
          "collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
          "defaultStatus": "affected"
        },
        {
          "cpes": [
            "cpe:/o:redhat:enterprise_linux:9"
          ],
          "vendor": "Red Hat",
          "product": "Red Hat Enterprise Linux 9",
          "packageName": "firefox",
          "collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
          "defaultStatus": "unaffected"
        },
        {
          "cpes": [
            "cpe:/o:redhat:enterprise_linux:9"
          ],
          "vendor": "Red Hat",
          "product": "Red Hat Enterprise Linux 9",
          "packageName": "thunderbird",
          "collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
          "defaultStatus": "affected"
        },
        {
          "cpes": [
            "cpe:/a:redhat:openshift_ai"
          ],
          "vendor": "Red Hat",
          "product": "Red Hat OpenShift AI (RHOAI)",
          "packageName": "rhoai/odh-workbench-codeserver-datascience-cpu-py312-rhel9",
          "collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
          "defaultStatus": "unaffected"
        },
        {
          "cpes": [
            "cpe:/a:redhat:openshift_devspaces:3"
          ],
          "vendor": "Red Hat",
          "product": "Red Hat OpenShift Dev Spaces",
          "packageName": "devspaces/dashboard-rhel9",
          "collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
          "defaultStatus": "unaffected"
        },
        {
          "cpes": [
            "cpe:/a:redhat:jboss_enterprise_bpms_platform:7"
          ],
          "vendor": "Red Hat",
          "product": "Red Hat Process Automation 7",
          "packageName": "handlebars",
          "collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
          "defaultStatus": "unaffected"
        }
      ]
    }
  ],
  "published": "2026-03-27T21:17:27.417",
  "references": [
    {
      "url": "https://github.com/handlebars-lang/handlebars.js/commit/68d8df5a88e0a26fe9e6084c5c6aaebe67b07da2",
      "tags": [
        "Patch"
      ],
      "source": "security-advisories@github.com"
    },
    {
      "url": "https://github.com/handlebars-lang/handlebars.js/releases/tag/v4.7.9",
      "tags": [
        "Release Notes"
      ],
      "source": "security-advisories@github.com"
    },
    {
      "url": "https://github.com/handlebars-lang/handlebars.js/security/advisories/GHSA-2w6w-674q-4c4q",
      "tags": [
        "Exploit",
        "Vendor Advisory"
      ],
      "source": "security-advisories@github.com"
    },
    {
      "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-2026-33937",
      "source": "0b0ca135-0b70-47e7-9f44-1890c2a1c46c"
    },
    {
      "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2452523",
      "source": "0b0ca135-0b70-47e7-9f44-1890c2a1c46c"
    },
    {
      "url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-33937.json",
      "source": "0b0ca135-0b70-47e7-9f44-1890c2a1c46c"
    }
  ],
  "vulnStatus": "Modified",
  "weaknesses": [
    {
      "type": "Secondary",
      "source": "security-advisories@github.com",
      "description": [
        {
          "lang": "en",
          "value": "CWE-94"
        },
        {
          "lang": "en",
          "value": "CWE-843"
        }
      ]
    },
    {
      "type": "Secondary",
      "source": "0b0ca135-0b70-47e7-9f44-1890c2a1c46c",
      "description": [
        {
          "lang": "en",
          "value": "CWE-94"
        }
      ]
    }
  ],
  "descriptions": [
    {
      "lang": "en",
      "value": "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."
    }
  ],
  "lastModified": "2026-09-04T13:19:25.650",
  "configurations": [
    {
      "nodes": [
        {
          "negate": false,
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:a:handlebarsjs:handlebars:*:*:*:*:*:node.js:*:*",
              "vulnerable": true,
              "matchCriteriaId": "A9D1F9A7-8359-4C3F-9932-4A085094F388",
              "versionEndExcluding": "4.7.9",
              "versionStartIncluding": "4.0.0"
            }
          ],
          "operator": "OR"
        }
      ]
    }
  ],
  "sourceIdentifier": "security-advisories@github.com"
}