CVE-2021-23979

Mozilla developers reported memory safety bugs present in Firefox 85. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code. This vulnerability affects Firefox < 86.

• CWE-787

• https://bugzilla.mozilla.org/buglist.cgi?bug_id=1663222%2C1666607%2C1672120%2C1678463%2C1678927%2C1679560%2C1681297%2C1681684%2C1683490%2C1684377%2C1684902Exploit, Issue Tracking, Vendor Advisory
• https://www.mozilla.org/security/advisories/mfsa2021-07/Release Notes, Vendor Advisory
• https://bugzilla.mozilla.org/buglist.cgi?bug_id=1663222%2C1666607%2C1672120%2C1678463%2C1678927%2C1679560%2C1681297%2C1681684%2C1683490%2C1684377%2C1684902Exploit, Issue Tracking, Vendor Advisory
• https://www.mozilla.org/security/advisories/mfsa2021-07/Release Notes, Vendor Advisory

Published

Feb 26, 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-2021-23973When trying to load a cross-origin resource in an audio/vide…6.5
• CVE-2021-23974The DOMParser API did not properly process '<noscript>' elem…6.1
• CVE-2021-23975The developer page about:memory has a Measure function for e…6.5
• CVE-2021-23976When accepting a malicious intent from other installed apps,…8.1
• CVE-2021-23977Firefox for Android suffered from a time-of-check-time-of-us…5.3
• CVE-2021-23978Mozilla developers reported memory safety bugs present in Fi…8.8
• CVE-2021-2398Vulnerability in the Oracle Advanced Outbound Telephony prod…8.1
• CVE-2021-23980A mutation XSS affects users calling bleach.clean with all o…6.1
• CVE-2021-23981A texture upload of a Pixel Buffer Object could have confuse…8.1
• CVE-2021-23982Using techniques that built on the slipstream research, a ma…6.5
• CVE-2021-23983By causing a transition on a parent node by removing a CSS r…6.5
• CVE-2021-23984A malicious extension could have opened a popup window lacki…6.5