{"id":"CVE-2026-118249","aliases":["GHSA-gfvx-2c2g-38wq"],"title":"Highcharts: series column construction writes to Object.prototype","titleSource":"OSV","descriptionSource":"OSV","declaredSeverity":"HIGH","description":"### Impact\nWhen series columns are built from point objects, the point option keys are used directly as data column ids, so the write that populates a column reaches `Object.prototype` and the `Object` constructor. Keys named `__proto__` and `constructor` survive `JSON.parse` as own enumerable properties, so an attacker who controls the point objects can set integer-keyed properties on `Object.prototype`, one per point index, to values of their choosing. Named properties cannot be reached this way. The integer keys still affect every object in the page: reading an out-of-range index on any array or plain object returns the attacker's value, and `for...in` over any object yields the injected keys, so unrelated code can take branches it should not using attacker-supplied data, and rendering can fail as a side effect. The properties remain in place once the chart has been built, and no user interaction is required beyond rendering the chart.\n\nConsequences beyond disruption depend on the consuming application.\n\n### Workarounds\nDrop-in fix - for any versions affected (6.1.0-13.0.2).\nAdd the below IIFE to run after Highcharts is loaded.\n\n```javascript\n;!function(t){if(t&&t.Point&&!t.Point.prototype.protoPollutionPatched){var o=t.Point.prototype,r=o.optionsToObject,e=o.setNestedProperty,n=Object.prototype.hasOwnProperty;o.optionsToObject=function(t){if(t&&\"object\"==typeof t&&!Array.isArray(t)&&(n.call(t,\"__proto__\")||n.call(t,\"constructor\"))){var o={};for(var e in t)n.call(t,e)&&!c(e)&&(o[e]=t[e]);t=o}return r.call(this,t)},o.setNestedProperty=function(t,o,r){return String(r).split(\".\").some(c)?t:e.call(this,t,o,r)},o.protoPollutionPatched=!0}function c(t){return\"__proto__\"===t||\"constructor\"===t}}(Highcharts);\n```\n\n[Live demo & testing](https://jsfiddle.net/BlackLabel/nopc6vhj/)\n\n### Obtaining the patched version\nThe patched releases are available from all the usual distribution channels. With npm, upgrade the affected package to the patched version listed above, for example `npm install highcharts@13.1.0`. If you load Highcharts from the CDN, use the versioned URLs on code.highcharts.com, for example `https://code.highcharts.com/13.1.0/highcharts.js`. For more on each installation method, see the [installation guide](https://www.highcharts.com/docs/getting-started/installation).","severity":"high","score":7.2,"published":"2026-10-28T17:57:18.323Z","modified":"2026-10-29T20:55:21.954Z","withdrawn":false,"knownExploited":false,"affected":[{"ecosystem":"npm","name":"highcharts","sources":[{"name":"OSV · GHSA-gfvx-2c2g-38wq","url":"https://osv.dev/vulnerability/GHSA-gfvx-2c2g-38wq"}],"ranges":[{"events":[{"introduced":"13.0.0"},{"fixed":"13.1.0"}],"type":"SEMVER"}],"versions":[],"fixed":["13.1.0"]}],"sourceAffected":[],"references":["https://github.com/highcharts/highcharts/security/advisories/GHSA-gfvx-2c2g-38wq","https://nvd.nist.gov/vuln/detail/CVE-2026-118249","https://github.com/highcharts/highcharts/pull/25321","https://github.com/highcharts/highcharts/commit/d3357705c8f348904441327e32f50ab528c3a205","https://github.com/highcharts/highcharts","https://github.com/highcharts/highcharts/releases/tag/v13.1.0"],"sources":[{"name":"OSV","id":"GHSA-gfvx-2c2g-38wq","modified":"2026-10-28T20:15:06.101208831Z","url":"https://osv.dev/vulnerability/GHSA-gfvx-2c2g-38wq"},{"name":"CVE","id":"CVE-2026-118249","modified":"2026-10-29T20:55:21.954Z","url":"https://www.cve.org/CVERecord?id=CVE-2026-118249"}],"assessments":[{"source":"OSV","vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:L/VA:H/SC:L/SI:L/SA:L","score":7.1},{"source":"GitHub_M","vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:H/VA:H/SC:L/SI:L/SA:L","score":7.2}],"cve":{"records":[{"id":"CVE-2026-118249","source":"GitHub_M","state":"PUBLISHED","reasons":[],"replacements":[],"disputed":false,"unsupportedWhenAssigned":false,"reserved":"2026-10-27T20:13:55.313Z","published":"2026-10-28T17:57:18.323Z","modified":"2026-10-29T20:55:21.954Z"}],"publishers":[{"name":"GitHub_M","role":"CNA","organizationId":"a0819718-46f1-4df5-94e2-005712e83aaa","modified":"2026-10-28T17:57:18.323Z"},{"name":"CISA-ADP","role":"ADP","organizationId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","modified":"2026-10-29T20:55:21.954Z"}],"references":[{"url":"https://github.com/highcharts/highcharts/security/advisories/GHSA-gfvx-2c2g-38wq","tags":["x_refsource_CONFIRM"],"source":"GitHub_M"},{"url":"https://github.com/highcharts/highcharts/pull/25321","tags":["x_refsource_MISC"],"source":"GitHub_M"},{"url":"https://github.com/highcharts/highcharts/commit/d3357705c8f348904441327e32f50ab528c3a205","tags":["x_refsource_MISC"],"source":"GitHub_M"},{"url":"https://github.com/highcharts/highcharts/releases/tag/v13.1.0","tags":["x_refsource_MISC"],"source":"GitHub_M"}],"weaknesses":[{"id":"CWE-1321","description":"CWE-1321: Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution')","source":"GitHub_M"}],"applicability":[],"prioritization":[{"source":"CISA-ADP","type":"SSVC","role":"CISA Coordinator","timestamp":"2026-10-29T15:28:32.137806Z","decisions":[{"name":"Exploitation","value":"none"},{"name":"Automatable","value":"no"},{"name":"Technical Impact","value":"partial"}]}]},"products":[{"vendor":"highcharts","name":"highcharts","platforms":[],"versions":[{"version":">= 13.0.0, < 13.1.0","status":"affected"}],"cpes":[],"source":"GitHub_M","url":"https://www.cve.org/CVERecord?id=CVE-2026-118249"}],"remediation":[],"observedAt":"2026-10-29T21:32:29.718Z","kev":{"status":"not-listed","checkedAt":"2026-10-31T05:40:30.632Z"},"coverage":[{"source":"NVD","status":"available","checkedAt":"2026-10-29T00:20:34.402Z","attemptedAt":"2026-10-29T00:20:34.402Z"},{"source":"GHSA","status":"available","checkedAt":"2026-10-29T00:20:34.491Z","attemptedAt":"2026-10-29T00:20:34.491Z"},{"source":"EUVD","status":"available","checkedAt":"2026-10-29T00:20:35.100Z","attemptedAt":"2026-10-29T00:20:35.100Z"},{"source":"EPSS","status":"no-result","checkedAt":"2026-10-29T00:20:34.189Z","attemptedAt":"2026-10-29T00:20:34.189Z"}],"evidence":[{"source":"NVD","id":"CVE-2026-118249","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-118249","modified":"2026-10-28T18:17:16.273","score":7.2,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:H/VA:H/SC:L/SI:L/SA:L/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X","checkedAt":"2026-10-29T00:20:34.402Z"},{"source":"GitHub Advisory Database","id":"GHSA-gfvx-2c2g-38wq","url":"https://github.com/advisories/GHSA-gfvx-2c2g-38wq","modified":"2026-10-28T19:56:15Z","checkedAt":"2026-10-29T00:20:34.491Z"},{"source":"ENISA EUVD","id":"EUVD-2026-112363","url":"https://euvd.enisa.europa.eu/vulnerability/EUVD-2026-112363","modified":"Oct 28, 2026, 5:57:18 PM","score":7.2,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:H/VA:H/SC:L/SI:L/SA:L","checkedAt":"2026-10-29T00:20:35.100Z"}],"aiSummary":{"text":"Highcharts versions 6.1.0-13.0.2 are affected by a prototype pollution vulnerability, allowing an attacker who controls point objects to set properties on Object.prototype. This can cause unrelated code to take unexpected branches and rendering to fail. The properties remain after the chart is built, without requiring user interaction.","model":"@cf/meta/llama-3.3-70b-instruct-fp8-fast","generatedAt":"2026-10-30T09:41:45.290Z","sources":[{"name":"OSV","url":"https://osv.dev/vulnerability/GHSA-gfvx-2c2g-38wq"},{"name":"CVE","url":"https://www.cve.org/CVERecord?id=CVE-2026-118249"}]}}