CVE-2021-29964

A locally-installed hostile program could send `WM_COPYDATA` messages that Firefox would process incorrectly, leading to an out-of-bounds read. *This bug only affects Firefox on Windows. Other operating systems are unaffected.*. This vulnerability affects Thunderbird < 78.11, Firefox < 89, and Firefox ESR < 78.11.

• CWE-125

• https://bugzilla.mozilla.org/show_bug.cgi?id=1706501Permissions Required, Vendor Advisory
• https://www.mozilla.org/security/advisories/mfsa2021-23/Release Notes, Vendor Advisory
• https://www.mozilla.org/security/advisories/mfsa2021-24/Release Notes, Vendor Advisory
• https://www.mozilla.org/security/advisories/mfsa2021-26/Release Notes, Vendor Advisory
• https://bugzilla.mozilla.org/show_bug.cgi?id=1706501Permissions Required, Vendor Advisory
• https://www.mozilla.org/security/advisories/mfsa2021-23/Release Notes, Vendor Advisory
• https://www.mozilla.org/security/advisories/mfsa2021-24/Release Notes, Vendor Advisory
• https://www.mozilla.org/security/advisories/mfsa2021-26/Release Notes, Vendor Advisory

Published

Jun 24, 2021

Last Modified

Jun 17, 2026

Status

Modified

• How Strix found a critical auth bypass in etcdStrix autonomously discovered a critical authentication bypass in etcd, later designated CVE-2026-33413.
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