CVE-2026-2776
Sandbox escape due to incorrect boundary conditions in the Telemetry component in External Software
- State
- Published
- Severity
- 10.0 Critical
- Published
- Feb 24, 2026
- Updated
- Jul 15, 2026
- Reserved
- Feb 19, 2026
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.
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 3.1 | 10.0 Critical | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H | CISA-ADP |
| 3.1 | 7.5 High | CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H | redhat-SADP |
Weaknesses
- CWE-119 Improper Restriction of Operations within the Bounds of a Memory Buffer
Affected Products
| Product | Versions |
|---|---|
FirefoxMozilla |
|
ThunderbirdMozilla |
|
References
- https://bugzilla.mozilla.org/show_bug.cgi?id=2015266
- https://www.mozilla.org/security/advisories/mfsa2026-13/
- https://www.mozilla.org/security/advisories/mfsa2026-14/
- https://www.mozilla.org/security/advisories/mfsa2026-15/
- https://www.mozilla.org/security/advisories/mfsa2026-16/
- https://www.mozilla.org/security/advisories/mfsa2026-17/
- https://access.redhat.com/security/cve/CVE-2026-2776vdb-entry
- RHBZ#2442291issue-tracking
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-2776.json
- https://access.redhat.com/errata/RHSA-2026:3984vendor-advisory
- https://access.redhat.com/errata/RHSA-2026:3976vendor-advisory
- https://access.redhat.com/errata/RHSA-2026:4260vendor-advisory
- https://access.redhat.com/errata/RHSA-2026:3361vendor-advisory
- https://access.redhat.com/errata/RHSA-2026:3517vendor-advisory
- https://access.redhat.com/errata/RHSA-2026:3338vendor-advisory
- https://access.redhat.com/errata/RHSA-2026:3515vendor-advisory
- https://access.redhat.com/errata/RHSA-2026:3492vendor-advisory
- https://access.redhat.com/errata/RHSA-2026:4432vendor-advisory
- https://access.redhat.com/errata/RHSA-2026:3491vendor-advisory
- https://access.redhat.com/errata/RHSA-2026:3980vendor-advisory
- https://access.redhat.com/errata/RHSA-2026:3495vendor-advisory
- https://access.redhat.com/errata/RHSA-2026:3979vendor-advisory
- https://access.redhat.com/errata/RHSA-2026:3494vendor-advisory
- https://access.redhat.com/errata/RHSA-2026:4022vendor-advisory
- https://access.redhat.com/errata/RHSA-2026:3493vendor-advisory
- https://access.redhat.com/errata/RHSA-2026:3983vendor-advisory
- https://access.redhat.com/errata/RHSA-2026:4152vendor-advisory
- https://access.redhat.com/errata/RHSA-2026:3978vendor-advisory
- https://access.redhat.com/errata/RHSA-2026:3496vendor-advisory
- https://access.redhat.com/errata/RHSA-2026:3981vendor-advisory
- https://access.redhat.com/errata/RHSA-2026:3497vendor-advisory
- https://access.redhat.com/errata/RHSA-2026:3982vendor-advisory
- https://access.redhat.com/errata/RHSA-2026:3339vendor-advisory
- https://access.redhat.com/errata/RHSA-2026:3516vendor-advisory
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