{"items":[{"id":"NVI-00012050","kind":"vulnerability","title":"Handlebars: JavaScript Injection via Own Property Check Bypass","revision":2,"unknowns":["Customer inventory, deployment, reachability and exploitation have not been inspected."],"lifecycle":"active","identifiers":["GHSA-p8wg-vrv2-v86f","CVE-2026-106445"],"plain_summary":"GitHub lists this reviewed advisory for handlebars. Published version ranges and source prerequisites are shown below; this is not an inspection of a visitor’s application.","review_status":"source_listed","control_topics":[],"public_actions":[{"summary":"Identify the exact component and deployed version, examine the linked publisher’s conditions, and retain evidence of any mitigation.","source_ids":["sr-3a6762c9bd516c55c939277102944bf5"],"action_type":"investigate","limitations":"Confirm current vendor support, compatibility and deployment evidence. This report has not tested a fix in your system.","current_supported_target":null}],"schema_version":"1.1.0","source_metrics":[{"kind":"EPSS","as_of":"2026-10-31T12:00:27.000Z","value":"0.589%","meaning":"FIRST EPSS model v2026.06.15; exploitation probability over 30 days, percentile 0.48165. Missing scores are unknown.","source_id":"sr-3a6762c9bd516c55c939277102944bf5"}],"why_it_matters":"Published affected context helps an owner decide what evidence to gather. This report has not examined your application.","related_sources":[{"id":"sr-9448869c524408c21d1330c6d81fbcb3","url":"https://github.com/advisories/GHSA-p8wg-vrv2-v86f","basis":"vendor_advisory","notes":"GitHub Advisory Database; CC-BY-4.0. Each advisory links its original attribution. Null normalizes fields.","title":"GHSA-p8wg-vrv2-v86f","publisher":"GitHub Advisory Database","observed_at":"2026-10-31T23:14:22.124Z"},{"id":"sr-3a6762c9bd516c55c939277102944bf5","url":"https://www.first.org/epss/data.html","basis":"official_catalog","notes":"FIRST EPSS; probability of exploitation in the next 30 days, not local compromise. Dataset date/model retained; FIRST services terms apply.","title":"CVE-2026-106445","publisher":"FIRST EPSS","observed_at":"2026-11-01T01:39:43.064Z"}],"affected_context":[{"certainty":"source_listed","source_ids":["sr-9448869c524408c21d1330c6d81fbcb3"],"technology":"handlebars","known_exclusions":[],"conditions_summary":"## Summary\n\nHandlebars can expose the `Function` constructor despite its prototype-access deny list. When a template reaches `Function.prototype`, its own `constructor` property is returned before the deny list is checked. An attacker who can render a controlled template with `allowProtoMethodsByDefault: true` can inject and execute arbitrary JavaScript, leading to Remote Code Execution on the server.\n\n## Description\n\n`lookupProperty` trusts own properties:\n\n```js\nif (Object.prototype.hasOwnProperty.call(parent, propertyName)) {\n  return result;\n}\n```\n\nNormally, prototype-derived values reach `resultIsAllowed`, which blocks dangerous method names such as `constructor`. However, `constructor` is itself an own property of prototype objects:\n\n```js\nFunction.prototype.constructor === Function;\nString.prototype.constructor === String;\nObject.prototype.constructor === Object;\n```\n\nAs a result, once a template reaches `Function.prototype`, looking up `constructor` returns `Function` without consulting the deny list.\n\n## Proof of Concept\n\nAn attacker needs to reach any prototype object where constructor is an own property, then access constructor to obtain Function. The shortest path requi","public_affected_ranges":[">= 3.0.0, <= 4.7.9"]}],"null_published_at":"2026-11-01T14:34:14.121Z","source_updated_at":"2026-10-12T14:33:17.000Z","source_disclosed_at":"2026-10-08T17:52:26.000Z","is_synthetic_fixture":false,"null_last_reviewed_at":null,"public_change_summary":"Dated EPSS estimate updated; this is not a new disclosure or proof of exploitation.","null_first_observed_at":"2026-10-31T23:14:22.124Z"},{"id":"NVI-00012050","kind":"vulnerability","title":"Handlebars: JavaScript Injection via Own Property Check Bypass","revision":1,"unknowns":["Customer inventory, deployment, reachability and exploitation have not been inspected."],"lifecycle":"active","identifiers":["GHSA-p8wg-vrv2-v86f","CVE-2026-106445"],"plain_summary":"GitHub lists this reviewed advisory for handlebars. Published version ranges and source prerequisites are shown below; this is not an inspection of a visitor’s application.","review_status":"source_listed","control_topics":[],"public_actions":[{"summary":"Identify the exact component and deployed version, examine the linked publisher’s conditions, and retain evidence of any mitigation.","source_ids":["sr-9448869c524408c21d1330c6d81fbcb3"],"action_type":"investigate","limitations":"Confirm current vendor support, compatibility and deployment evidence. This report has not tested a fix in your system.","current_supported_target":null}],"schema_version":"1.1.0","source_metrics":[],"why_it_matters":"Published affected context helps an owner decide what evidence to gather. This report has not examined your application.","related_sources":[{"id":"sr-9448869c524408c21d1330c6d81fbcb3","url":"https://github.com/advisories/GHSA-p8wg-vrv2-v86f","basis":"vendor_advisory","notes":"GitHub Advisory Database; CC-BY-4.0. Each advisory links its original attribution. Null normalizes fields.","title":"GHSA-p8wg-vrv2-v86f","publisher":"GitHub Advisory Database","observed_at":"2026-10-31T23:14:22.124Z"}],"affected_context":[{"certainty":"source_listed","source_ids":["sr-9448869c524408c21d1330c6d81fbcb3"],"technology":"handlebars","known_exclusions":[],"conditions_summary":"## Summary\n\nHandlebars can expose the `Function` constructor despite its prototype-access deny list. When a template reaches `Function.prototype`, its own `constructor` property is returned before the deny list is checked. An attacker who can render a controlled template with `allowProtoMethodsByDefault: true` can inject and execute arbitrary JavaScript, leading to Remote Code Execution on the server.\n\n## Description\n\n`lookupProperty` trusts own properties:\n\n```js\nif (Object.prototype.hasOwnProperty.call(parent, propertyName)) {\n  return result;\n}\n```\n\nNormally, prototype-derived values reach `resultIsAllowed`, which blocks dangerous method names such as `constructor`. However, `constructor` is itself an own property of prototype objects:\n\n```js\nFunction.prototype.constructor === Function;\nString.prototype.constructor === String;\nObject.prototype.constructor === Object;\n```\n\nAs a result, once a template reaches `Function.prototype`, looking up `constructor` returns `Function` without consulting the deny list.\n\n## Proof of Concept\n\nAn attacker needs to reach any prototype object where constructor is an own property, then access constructor to obtain Function. The shortest path requi","public_affected_ranges":[">= 3.0.0, <= 4.7.9"]}],"null_published_at":"2026-11-01T01:03:56.626Z","source_updated_at":"2026-10-12T14:33:17.000Z","source_disclosed_at":"2026-10-08T17:52:26.000Z","is_synthetic_fixture":false,"null_last_reviewed_at":null,"public_change_summary":"First indexed by Null; source disclosure date is shown separately.","null_first_observed_at":"2026-10-31T23:14:22.124Z"}],"next_cursor":null,"snapshot_revision":"42594"}