{"cve":"CVE-2026-100821","nvd":{"published":"2026-09-29T13:17:47.400","modified":"2026-10-13T17:13:58.030","status":"Analyzed","description":"Site isolation issue in the Panning and Zooming component. This vulnerability was fixed in Firefox ESR 153.4, Thunderbird 157, Thunderbird 140.17, Thunderbird 153.4, Firefox 157, Firefox ESR 115.42, and Firefox ESR 140.17.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:N/A:N","score":4.7},"cwes":["CWE-346"],"references":["https://bugzilla.mozilla.org/show_bug.cgi?id=2071784","https://www.mozilla.org/security/advisories/mfsa2026-100/","https://www.mozilla.org/security/advisories/mfsa2026-101/","https://www.mozilla.org/security/advisories/mfsa2026-102/","https://www.mozilla.org/security/advisories/mfsa2026-103/"],"products":["mozilla:firefox","mozilla:thunderbird"],"source":"nvd","synced_at":"2026-10-19T22:56:48.555445741+00:00"},"epss":{"cve":"CVE-2026-100821","score":0.00143,"percentile":0.03559,"date":"2026-10-25"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}