CVE-2026-2776
Modified
Modified - Updated After Analysis
Sandbox Escape in Firefox Telemetry via Boundary Condition Error
Vulnerability report for CVE-2026-2776, including description, CVSS score, EPSS score, affected products, exploitability, helpful resources, and attack-flow context.
Publication date: 2026-02-24
Last updated on: 2026-06-30
Assigner: Mozilla Corporation
Description
Description
Sandbox escape due to incorrect boundary conditions in the Telemetry component in External Software. This vulnerability was fixed in Firefox 148, Firefox ESR 115.33, Firefox ESR 140.8, Thunderbird 148, and Thunderbird 140.8.
CVSS Scores
EPSS Scores
| Probability: | |
| Percentile: |
Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| mozilla | firefox | to 148.0 (exc) |
| mozilla | thunderbird | to 148.0 (exc) |
| mozilla | firefox | to 115.33.0 (exc) |
| mozilla | firefox | From 128.0 (inc) to 140.8.0 (exc) |
| mozilla | thunderbird | to 140.8.0 (exc) |
Helpful Resources
Exploitability
CWE
KEV
| CWE ID | Description |
|---|---|
| CWE-119 | The product performs operations on a memory buffer, but it reads from or writes to a memory location outside the buffer's intended boundary. This may result in read or write operations on unexpected memory locations that could be linked to other variables, data structures, or internal program data. |
