VULNERABILITY INTELLIGENCE
CVE-2020-26961
CVSS score6.5 MEDIUM
EPSS probability1.17%
CISA KEVNot currently listed
Published2020-12-09
Last modified2026-06-17
CVSS vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N
Description
When DNS over HTTPS is in use, it intentionally filters RFC1918 and related IP ranges from the responses as these do not make sense coming from a DoH resolver. However when an IPv4 address was mapped through IPv6, these addresses were erroneously let through, leading to a potential DNS Rebinding attack. This vulnerability affects Firefox < 83, Firefox ESR < 78.5, and Thunderbird < 78.5.
Primary references
- security@mozilla.org — Issue Tracking, Permissions Required, Vendor Advisory
- security@mozilla.org — Vendor Advisory
- security@mozilla.org — Vendor Advisory
- security@mozilla.org — Vendor Advisory
- af854a3a-2127-422b-91ae-364da2661108 — Issue Tracking, Permissions Required, Vendor Advisory
- af854a3a-2127-422b-91ae-364da2661108 — Vendor Advisory
- af854a3a-2127-422b-91ae-364da2661108 — Vendor Advisory
- af854a3a-2127-422b-91ae-364da2661108 — Vendor Advisory