CVE-2017-7764 Other in Firefox

What is CVE-2017-7764?

CVE-2017-7764 is a medium-severity vulnerability in Debian Debian Linux, published on 11 Jun 2018. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official 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.

Weakness: CWE-20

Which versions are affected by CVE-2017-7764?

It affects 3 products.

Products include Debian Debian Linux, Mozilla Firefox, Mozilla Thunderbird.

How do I fix CVE-2017-7764?

Upgrade to a fixed version.

Is CVE-2017-7764 being exploited?

There is no known exploitation of CVE-2017-7764 in the wild and no public exploit code.

Other vulnerabilities in Debian Debian Linux

• CVE-2015-3306 ProFTPD Improper Access Control Exploited Critical 10.0
• CVE-2025-49113 RoundCube Webmail Deserialization of Untrusted Data Exploited Critical 9.9
• CVE-2026-24061 GNU InetUtils Argument Injection Exploited Critical 9.8
• CVE-2025-39682 Linux Kernel Improper Check for Unusual or Exceptional Conditions Exploited Critical 9.8
• CVE-2024-9680 Mozilla Firefox Use-After-Free Exploited Critical 9.8

All Debian Debian Linux vulnerabilities

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as DEBIAN-CVE-2017-7764, GHSA-mc3w-fw7x-qrw7, UBUNTU-CVE-2017-7764.