Executive brief
Mozilla has released security updates to address a vulnerability in the Firefox web browser's developer tools. This flaw could allow for the unauthorized disclosure of information through the DevTools framework. An exploit could potentially expose sensitive data to an attacker, though the impact is considered moderate compared to other browser vulnerabilities.
Technical details
An information disclosure vulnerability exists in the Framework component of Mozilla Firefox's Developer Tools (DevTools). The flaw allows for the unintended exposure of data, though specific details regarding the root cause are restricted in the associated Bugzilla report (Bug 2027519). The vulnerability is reachable via the network if a user interacts with malicious content while DevTools is active or through specific framework interactions. Mozilla has addressed this issue in Firefox version 153 and Firefox ESR version 140.13. An attacker could potentially leverage this to access information that should otherwise be protected by the browser's security boundaries.
Affected products
- Mozilla Firefox Before 153
- Mozilla Firefox ESR Before 140.13
Timeline
- 2026-07-21: advisory
- 2026-07-21: patched