CVE-2020-26966

Searching for a single word from the address bar caused an mDNS request to be sent on the local network searching for a hostname consisting of that string; resulting in an information leak. *Note: This issue only affected Windows operating systems. Other operating systems are unaffected.*. This vulnerability affects Firefox < 83, Firefox ESR < 78.5, and Thunderbird < 78.5.

• https://bugzilla.mozilla.org/show_bug.cgi?id=1663571Issue Tracking, Permissions Required, Vendor Advisory
• https://www.mozilla.org/security/advisories/mfsa2020-50/Vendor Advisory
• https://www.mozilla.org/security/advisories/mfsa2020-51/Vendor Advisory
• https://www.mozilla.org/security/advisories/mfsa2020-52/Vendor Advisory
• https://bugzilla.mozilla.org/show_bug.cgi?id=1663571Issue Tracking, Permissions Required, Vendor Advisory
• https://www.mozilla.org/security/advisories/mfsa2020-50/Vendor Advisory
• https://www.mozilla.org/security/advisories/mfsa2020-51/Vendor Advisory
• https://www.mozilla.org/security/advisories/mfsa2020-52/Vendor Advisory

Published

Dec 9, 2020

Last Modified

Jun 17, 2026

Status

Modified

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