CVE-2026-2761 — Protection Mechanism Failure in Mozilla Firefox

CWE-693 — Protection Mechanism Failure13 documents9 sources
Severity
10.0CRITICALNVD
EPSS
0.1%
top 65.98%
CISA KEV
Not in KEV
Exploit
No known exploits
Affected products
2
Mozilla ThunderbirdMozilla Firefox
Timeline
PublishedFeb 24

Description

Sandbox escape in the Graphics: WebRender component. This vulnerability was fixed in Firefox 148, Firefox ESR 115.33, Firefox ESR 140.8, Thunderbird 148, and Thunderbird 140.8.

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:HExploitability: 3.9 | Impact: 6.0

Affected Packages3 packages

▶NVDmozilla/firefox128.0 — 140.8.0+2
▶NVDmozilla/thunderbird< 140.8.0+1
▶Debianmozilla/thunderbird< 1:140.8.0esr-1~deb11u1+3

🔴Vulnerability Details

3
OSV
CVE-2026-2761: Sandbox escape in the Graphics: WebRender component↗2026-02-24
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CVEList
Sandbox escape in the Graphics: WebRender component↗2026-02-24
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GHSA
GHSA-g5w7-69g8-vcwp: Sandbox escape in the Graphics: WebRender component↗2026-02-24
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📋Vendor Advisories

7
Red Hat
firefox: thunderbird: Sandbox escape in the Graphics: WebRender component↗2026-02-24
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Debian
CVE-2026-2761: firefox - Sandbox escape in the Graphics: WebRender component. This vulnerability affects ...↗2026
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Mozilla
Mozilla Foundation Security Advisory 2026-13: CVE-2026-2761↗
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Mozilla
Mozilla Foundation Security Advisory 2026-17: CVE-2026-2761↗
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Mozilla
Mozilla Foundation Security Advisory 2026-14: CVE-2026-2761↗
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🕵️Threat Intelligence

1
Wiz
CVE-2026-2761 Impact, Exploitability, and Mitigation Steps | Wiz↗
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💬Community

1
Bugzilla
CVE-2026-2761 firefox: thunderbird: Sandbox escape in the Graphics: WebRender component↗2026-02-24
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CVE-2026-2761 — Protection Mechanism Failure in Mozilla | cvebase