CVE-2010-3765 Mozilla Multiple Products Remote Code Execution

What is CVE-2010-3765?

CVE-2010-3765 is a critical memory corruption vulnerability in Mozilla Firefox, published on 27 Oct 2010. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

Mozilla Firefox 3.5.x through 3.5.14 and 3.6.x through 3.6.11, Thunderbird 3.1.6 before 3.1.6 and 3.0.x before 3.0.10, and SeaMonkey 2.x before 2.0.10, when JavaScript is enabled, allows remote attackers to execute arbitrary code via vectors related to nsCSSFrameConstructor::ContentAppended, the appendChild method, incorrect index tracking, and the creation of multiple frames, which triggers memory corruption, as exploited in the wild in October 2010 by the Belmoo malware.

Weakness: CWE-119

Which versions are affected by CVE-2010-3765?

It affects 3 products.

Products include Mozilla Firefox, Mozilla Seamonkey, Mozilla Thunderbird.

How do I fix CVE-2010-3765?

Upgrade to a fixed version. US federal agencies must fix it by 27 Oct 2025.

Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.

Is CVE-2010-3765 being exploited?

Yes. Attackers have exploited CVE-2010-3765 in the wild since at least 6 Oct 2025.

Public exploit code: 1 Metasploit module and 4 Exploit-DB entries.

Other vulnerabilities in Mozilla Firefox

• CVE-2019-11708 Mozilla Firefox and Thunderbird Sandbox Escape Exploited Critical 10.0
• CVE-2022-26486 Mozilla Firefox Use-After-Free Exploited Critical 9.6
• CVE-2022-26485 Mozilla Firefox Use-After-Free Exploited High 8.8
• CVE-2019-11707 Mozilla Firefox and Thunderbird Type Confusion Exploited High 8.8
• CVE-2020-6819 Mozilla Firefox And Thunderbird Use-After-Free Exploited High 8.1

All Mozilla Firefox vulnerabilities

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as GHSA-cmrc-q43h-xrrq, RHSA-2010:0808, RHSA-2010:0809, RHSA-2010:0810, RHSA-2010:0812.