CVE-2025-2817 Privilege escalation in Thunderbird Updater

What is CVE-2025-2817?

CVE-2025-2817 is a high-severity vulnerability in Mozilla Firefox, published on 29 Apr 2025. Any signed-in user can exploit it over the network, with no action from the victim.

Official description

Thunderbird's update mechanism allowed a medium-integrity user process to interfere with the SYSTEM-level updater by manipulating the file-locking behavior. By injecting code into the user-privileged process, an attacker could bypass intended access controls, allowing SYSTEM-level file operations on paths controlled by a non-privileged user and enabling privilege escalation. This vulnerability was fixed in Firefox 138, Firefox ESR 128.10, Firefox ESR 115.23, Thunderbird 138, and Thunderbird 128.10.

Weakness: CWE-22

Which versions are affected by CVE-2025-2817?

It affects 2 products.

Products include Mozilla Firefox, Mozilla Thunderbird.

How do I fix CVE-2025-2817?

Upgrade to a fixed version.

Is CVE-2025-2817 being exploited?

There is no known exploitation of CVE-2025-2817 in the wild and no public exploit code.

Other vulnerabilities in Mozilla Firefox

• CVE-2019-11708 Mozilla Firefox and Thunderbird Sandbox Escape Exploited Critical 10.0
• CVE-2010-3765 Mozilla Multiple Products Remote Code Execution Exploited Critical 9.8
• 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

All Mozilla Firefox vulnerabilities

Sources

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

Also known as GHSA-j657-7g4v-wv6h, SUSE-SU-2025:1414-1, openSUSE-SU-2025:15040-1.