Insufficient vetting of parameters passed with the Prompt:Open IPC message between child and parent processes can result in the non-sandboxed parent process opening web content chosen by a compromised child process. When combined with additional vulnerabilities this could result in executing arbitrary code on the user's computer. This vulnerability affects Firefox ESR < 60.7.2, Firefox < 67.0.4, and Thunderbird < 60.7.2.
Insufficient vetting of parameters passed with the Prompt:Open IPC message between child and parent processes can result in the non-sandboxed parent process opening web content chosen by a compromised child process. When combined with additional vulnerabilities this could result in executing arbitrary code on the user's computer. This vulnerability affects Firefox ESR < 60.7.2, Firefox < 67.0.4, and Thunderbird < 60.7.2.
Why this VPI (explainable, experimental)
VPI breakdown
| Impact | 100.00 |
| Exploitation signal(KEV listed) | ×1.50 |
| VPI | 100.00 |
VPI formula vpi-v1
Required Action
Apply updates per vendor instructions.
| Source | CVSS Version | Base Score | Severity | Vector String | Assessment Date |
|---|---|---|---|---|---|
| NVDNIST | 3.1 | 10.0 | CRITICAL | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H | 04/20/2026 |
| NVDNIST | 2.0 | 10.0 |
| AV:N/AC:L/Au:N/C:C/I:C/A:C |
| 04/20/2026 |