{"id":"CVE-2026-84942","aliases":["EUVD-2026-74074","GHSA-r4c3-6c67-qqwx"],"status":"published","title":"Stored Cross-Site Scripting via Vega Expression Function Bypass in OpenSearch Dashboards","description":"Improper input validation in the Vega expression function implementation in OpenSearch Dashboards allows a remote authenticated actor with dashboard write permissions to execute arbitrary JavaScript in the context of other users' browser sessions by saving a crafted Vega visualization. The checkForFunctionProperty validation routine failed to recurse into arrays of objects, allowing a function property nested inside an array to bypass validation.","severity":{"version":"4.0","score":6.3,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:N/VI:N/VA:N/SC:H/SI:H/SA:N","level":"medium","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-12","score":0.00544,"percentile":0.46164,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-79"],"published":"2026-09-08T19:41:25Z","modified":"2026-10-28T02:30:57Z","products":[{"vendor":"aws","product":"amazon opensearch service"},{"vendor":"opensearch","product":"opensearch dashboards"}],"references":[{"url":"https://github.com/opensearch-project/OpenSearch-Dashboards/releases/tag/3.6.0","tags":["patch","fix"]},{"url":"https://github.com/opensearch-project/OpenSearch-Dashboards/releases/tag/2.19.5","tags":["patch","fix"]},{"url":"https://aws.amazon.com/security/security-bulletins/2026-102-aws/","tags":["vendor-advisory","advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-84942","tags":["advisory"]},{"url":"https://aws.amazon.com/security/security-bulletins/2026-102-aws"},{"url":"https://github.com/advisories/GHSA-r4c3-6c67-qqwx"},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/84xxx/CVE-2026-84942.json","tags":["advisory"]}],"sources":{"cve":[{"id":"CVE-2026-84942","title":"Stored Cross-Site Scripting via Vega Expression Function Bypass in OpenSearch Dashboards","description":"Improper input validation in the Vega expression function implementation in OpenSearch Dashboards allows a remote authenticated actor with dashboard write permissions to execute arbitrary JavaScript in the context of other users' browser sessions by saving a crafted Vega visualization. The checkForFunctionProperty validation routine failed to recurse into arrays of objects, allowing a function property nested inside an array to bypass validation.","status":"published","published":"2026-09-08T19:41:25.224Z","modified":"2026-09-09T20:51:34.759Z","cvss":[{"version":"4.0","score":6.3,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:N/VI:N/VA:N/SC:H/SI:H/SA:N","level":"medium","assessor":"cna"},{"version":"3.1","score":8.7,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:N","level":"high","assessor":"cna"}],"cwes":["CWE-79"],"updated_at":"2026-11-02T14:20:08.391556Z"}],"euvd":[{"id":"EUVD-2026-74074","description":"Improper input validation in the Vega expression function implementation in OpenSearch Dashboards allows a remote authenticated actor with dashboard write permissions to execute arbitrary JavaScript in the context of other users' browser sessions by saving a crafted Vega visualization. The checkForFunctionProperty validation routine failed to recurse into arrays of objects, allowing a function property nested inside an array to bypass validation.","status":"published","published":"2026-09-08T19:41:25Z","modified":"2026-09-09T20:51:34Z","cvss":[{"version":"4.0","score":6.3,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:N/VI:N/VA:N/SC:H/SI:H/SA:N","level":"medium"}],"updated_at":"2026-11-02T17:28:25.986684Z"}],"ghsa":[{"id":"GHSA-r4c3-6c67-qqwx","title":"Improper input validation in the Vega expression function implementation in OpenSearch Dashboards...","description":"Improper input validation in the Vega expression function implementation in OpenSearch Dashboards allows a remote authenticated actor with dashboard write permissions to execute arbitrary JavaScript in the context of other users' browser sessions by saving a crafted Vega visualization. The checkForFunctionProperty validation routine failed to recurse into arrays of objects, allowing a function property nested inside an array to bypass validation.","status":"published","published":"2026-09-08T21:34:29Z","modified":"2026-09-08T21:34:37Z","cvss":[{"version":"4.0","score":6.3,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:N/VI:N/VA:N/SC:H/SI:H/SA:N/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","level":"medium"},{"version":"3.1","score":8.7,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:N","level":"high"}],"cwes":["CWE-79"],"updated_at":"2026-11-02T15:11:36.851913Z"}],"nvd":[{"id":"CVE-2026-84942","description":"Improper input validation in the Vega expression function implementation in OpenSearch Dashboards allows a remote authenticated actor with dashboard write permissions to execute arbitrary JavaScript in the context of other users' browser sessions by saving a crafted Vega visualization. The checkForFunctionProperty validation routine failed to recurse into arrays of objects, allowing a function property nested inside an array to bypass validation.","status":"published","published":"2026-09-08T20:18:51.307Z","modified":"2026-09-09T21:17:05.473Z","cvss":[{"version":"4.0","score":6.3,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:N/VI:N/VA:N/SC:H/SI:H/SA:N/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","level":"medium","assessor":"secondary"},{"version":"3.1","score":8.7,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:N","level":"high","assessor":"secondary"}],"cwes":["CWE-79"],"updated_at":"2026-11-02T14:12:45.612639Z"}],"osv":[{"id":"CVE-2026-84942","title":"Stored Cross-Site Scripting via Vega Expression Function Bypass in OpenSearch Dashboards","description":"Improper input validation in the Vega expression function implementation in OpenSearch Dashboards allows a remote authenticated actor with dashboard write permissions to execute arbitrary JavaScript in the context of other users' browser sessions by saving a crafted Vega visualization. The checkForFunctionProperty validation routine failed to recurse into arrays of objects, allowing a function property nested inside an array to bypass validation.","status":"published","published":"2026-09-08T19:41:25.224Z","modified":"2026-10-28T02:30:57.195161634Z","cvss":[{"version":"4.0","score":6.3,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:N/VI:N/VA:N/SC:H/SI:H/SA:N","level":"medium"}],"cwes":["CWE-79"],"updated_at":"2026-11-02T15:45:18.482949Z"}]}}