{"cve":"CVE-2017-7764","nvd":{"published":"2018-06-11T21:29:08.437","modified":"2026-06-17T01:25:09.023","status":"Modified","description":"Characters from the \"Canadian Syllabics\" unicode block can be mixed with characters from other unicode blocks in the addressbar instead of being rendered as their raw \"punycode\" form, allowing for domain name spoofing attacks through character confusion. The current Unicode standard allows characters from \"Aspirational Use Scripts\" such as Canadian Syllabics to be mixed with Latin characters in the \"moderately restrictive\" IDN profile. We have changed Firefox behavior to match the upcoming Unicode version 10.0 which removes this category and treats them as \"Limited Use Scripts.\". This vulnerability affects Firefox < 54, Firefox ESR < 52.2, and Thunderbird < 52.2.","cvss_v4":null,"cvss_v3":{"version":"3.0","vector":"CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N","score":5.3},"cwes":["CWE-20"],"references":["http://www.securityfocus.com/bid/99057","http://www.securitytracker.com/id/1038689","http://www.unicode.org/reports/tr31/tr31-26.html#Aspirational_Use_Scripts","https://access.redhat.com/errata/RHSA-2017:1440","https://access.redhat.com/errata/RHSA-2017:1561"],"products":["debian:debian_linux","mozilla:firefox","mozilla:thunderbird"],"source":"nvd","synced_at":"2026-10-19T20:51:47.459859389+00:00"},"epss":{"cve":"CVE-2017-7764","score":0.01962,"percentile":0.80325,"date":"2026-10-31"},"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."]}