CVE-2025-2817: mozilla firefox Path Traversal

Vulnerability summary

CVE-2025-2817 is a high (CVSS 8.8) Path Traversal vulnerability in mozilla firefox. EPSS estimates a 0.66% chance of exploitation in the next 30 days, higher than 50.5% of scored vulnerabilities.

Timeline

1. 29-04-2025
   PublishedVulnerability first disclosed.
2. 13-04-2026
   Last modifiedVulnerability information updated.

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.

• CWE-22Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')The product uses external input to construct a pathname that is intended to identify a file or directory that is located underneath a restricted parent directory, but the product does not properly neutralize special elements within the pathname that can cause the pathname to resolve to a location that is outside of the restricted directory.