CVE-2021-29955

A transient execution vulnerability, named Floating Point Value Injection (FPVI) allowed an attacker to leak arbitrary memory addresses and may have also enabled JIT type confusion attacks. (A related vulnerability, Speculative Code Store Bypass (SCSB), did not affect Firefox.). This vulnerability affects Firefox ESR < 78.9 and Firefox < 87.

• CWE-74

• https://bugzilla.mozilla.org/show_bug.cgi?id=1692972Permissions Required, Vendor Advisory
• https://www.mozilla.org/security/advisories/mfsa2021-10/Release Notes, Vendor Advisory
• https://www.mozilla.org/security/advisories/mfsa2021-11/Release Notes, Vendor Advisory
• https://bugzilla.mozilla.org/show_bug.cgi?id=1692972Permissions Required, Vendor Advisory
• https://www.mozilla.org/security/advisories/mfsa2021-10/Release Notes, Vendor Advisory
• https://www.mozilla.org/security/advisories/mfsa2021-11/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.
• Autonomous PentestingAI agents that find and validate exploitable vulnerabilities like this one across your applications.
• PR ReviewsPentest every pull request so vulnerable code is caught before it ships to production.
• AI Penetration TestingHow AI-driven penetration testing continuously covers your attack surface.

• CVE-2021-29949When loading the shared library that provides the OTR protoc…7.8
• CVE-2021-29950Thunderbird unprotects a secret OpenPGP key prior to using i…7.5
• CVE-2021-29951The Mozilla Maintenance Service granted SERVICE_START access…6.5
• CVE-2021-29952When Web Render components were destructed, a race condition…7.5
• CVE-2021-29953A malicious webpage could have forced a Firefox for Android …6.1
• CVE-2021-29954Proxy functionality built into Hubs Cloud’s Reticulum softwa…9.8
• CVE-2021-29956OpenPGP secret keys that were imported using Thunderbird ver…4.3
• CVE-2021-29957If a MIME encoded email contains an OpenPGP inline signed or…4.3
• CVE-2021-29958When a download was initiated, the client did not check whet…4.3
• CVE-2021-29959When a user has already allowed a website to access micropho…4.3
• CVE-2021-29960Firefox used to cache the last filename used for printing a …4.3
• CVE-2021-29961When styling and rendering an oversized `<select>` element, …4.3