CVE-2026-2761
published 2026-02-24CVE-2026-2761: 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…
PriorityP354critical10CVSS 3.1
AVNACLPRNUINSCCHIHAH
EPSS
0.40%
32.2th percentile
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.
Affected
13 ranges
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| debian | firefox | < firefox 148.0-1 (sid) | firefox 148.0-1 (sid) |
| debian | firefox-esr | < firefox 148.0-1 (sid) | firefox 148.0-1 (sid) |
| debian | thunderbird | < firefox 148.0-1 (sid) | firefox 148.0-1 (sid) |
| mozilla | firefox | < 115.33.0 | 115.33.0 |
| mozilla | firefox | < 148.0 | 148.0 |
| mozilla | firefox | — | — |
| mozilla | firefox | >= 128.0 < 140.8.0 | 140.8.0 |
| mozilla | thunderbird | < 140.8.0 | 140.8.0 |
| mozilla | thunderbird | < 148.0 | 148.0 |
| mozilla | thunderbird | >= 0 < 1:140.8.0esr-1~deb11u1 | 1:140.8.0esr-1~deb11u1 |
| mozilla | thunderbird | >= 0 < 1:140.8.0esr-1~deb12u1 | 1:140.8.0esr-1~deb12u1 |
| mozilla | thunderbird | >= 0 < 1:140.8.0esr-1~deb13u1 | 1:140.8.0esr-1~deb13u1 |
| mozilla | thunderbird | >= 0 < 1:140.8.0esr-1 | 1:140.8.0esr-1 |
CVSS provenance
nvdv3.110.0CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
osv10.0CRITICAL
vendor_debian10.0CRITICAL
vendor_redhat10.0CRITICAL
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Red Hat
firefox: thunderbird: Sandbox escape in the Graphics: WebRender component
vendor_redhat·2026-02-24·CVSS 10.0
CVE-2026-2761 [CRITICAL] firefox: thunderbird: Sandbox escape in the Graphics: WebRender component
firefox: thunderbird: Sandbox escape in the Graphics: WebRender component
Sandbox escape in the Graphics: WebRender component. This vulnerability affects Firefox < 148, Firefox ESR < 115.33, Firefox ESR < 140.8, Thunderbird < 148, and Thunderbird < 140.8.
A flaw was found in Firefox and Thunderbird. The Mozilla Foundation's Security Advisory describes the following issue:
Sandbox escape in the Graphics: WebRender component
Statement: Red Hat Product Security rates the severity of this flaw as determined by the Mozilla Foundation Security Advisory.
Package: rhel10/firefox-flatpak (Red Hat Enterprise Linux 10) - Affected
Package: rhel10/thunderbird-flatpak (Red Hat Enterprise Linux 10) - Affected
Package: firefox (Red Hat Enterprise Linux 6) - Out of support scope
Package: thunderbird
Debian
CVE-2026-2761: firefox - Sandbox escape in the Graphics: WebRender component. This vulnerability affects ...
vendor_debian·2026·CVSS 10.0
CVE-2026-2761 [CRITICAL] CVE-2026-2761: firefox - Sandbox escape in the Graphics: WebRender component. This vulnerability affects ...
Sandbox escape in the Graphics: WebRender component. This vulnerability affects Firefox < 148, Firefox ESR < 115.33, Firefox ESR < 140.8, Thunderbird < 148, and Thunderbird < 140.8.
Scope: local
sid: resolved (fixed in 148.0-1)
Mozilla
Mozilla Foundation Security Advisory 2026-13: CVE-2026-2761
vendor_mozilla·CVSS 10.0
CVE-2026-2761 [CRITICAL] Mozilla Foundation Security Advisory 2026-13: CVE-2026-2761
Mozilla Foundation Security Advisory 2026-13
CVE: CVE-2026-2761
Product: Firefox
Impact: high
Fixed in: Firefox 148
Mozilla
Mozilla Foundation Security Advisory 2026-17: CVE-2026-2761
vendor_mozilla·CVSS 10.0
CVE-2026-2761 [CRITICAL] Mozilla Foundation Security Advisory 2026-17: CVE-2026-2761
Mozilla Foundation Security Advisory 2026-17
CVE: CVE-2026-2761
Product: Thunderbird
Impact: high
Fixed in: Thunderbird 140.8
Mozilla
Mozilla Foundation Security Advisory 2026-14: CVE-2026-2761
vendor_mozilla·CVSS 10.0
CVE-2026-2761 [CRITICAL] Mozilla Foundation Security Advisory 2026-14: CVE-2026-2761
Mozilla Foundation Security Advisory 2026-14
CVE: CVE-2026-2761
Product: Firefox ESR
Impact: high
Fixed in: Firefox ESR 115.33
Mozilla
Mozilla Foundation Security Advisory 2026-16: CVE-2026-2761
vendor_mozilla·CVSS 10.0
CVE-2026-2761 [CRITICAL] Mozilla Foundation Security Advisory 2026-16: CVE-2026-2761
Mozilla Foundation Security Advisory 2026-16
CVE: CVE-2026-2761
Product: Thunderbird
Impact: high
Fixed in: Thunderbird 148
Mozilla
Mozilla Foundation Security Advisory 2026-15: CVE-2026-2761
vendor_mozilla·CVSS 10.0
CVE-2026-2761 [CRITICAL] Mozilla Foundation Security Advisory 2026-15: CVE-2026-2761
Mozilla Foundation Security Advisory 2026-15
CVE: CVE-2026-2761
Product: Firefox ESR
Impact: high
Fixed in: Firefox ESR 140.8
OSV
CVE-2026-2761: Sandbox escape in the Graphics: WebRender component
osv·2026-02-24·CVSS 10.0
CVE-2026-2761 [CRITICAL] CVE-2026-2761: Sandbox escape in the Graphics: WebRender component
Sandbox escape in the Graphics: WebRender component. This vulnerability affects Firefox < 148, Firefox ESR < 115.33, Firefox ESR < 140.8, Thunderbird < 148, and Thunderbird < 140.8.
GHSA
GHSA-g5w7-69g8-vcwp: Sandbox escape in the Graphics: WebRender component
ghsa_unreviewed·2026-02-24
CVE-2026-2761 [CRITICAL] CWE-693 GHSA-g5w7-69g8-vcwp: Sandbox escape in the Graphics: WebRender component
Sandbox escape in the Graphics: WebRender component. This vulnerability affects Firefox < 148, Firefox ESR < 115.33, and Firefox ESR < 140.8.
No detection rules found.
No public exploits indexed.
Bugzilla
CVE-2026-2761 firefox: thunderbird: Sandbox escape in the Graphics: WebRender component
bugzilla·2026-02-24·CVSS 10.0
CVE-2026-2761 [CRITICAL] CVE-2026-2761 firefox: thunderbird: Sandbox escape in the Graphics: WebRender component
CVE-2026-2761 firefox: thunderbird: Sandbox escape in the Graphics: WebRender component
Sandbox escape in the Graphics: WebRender component. This vulnerability affects Firefox < 148, Firefox ESR < 115.33, and Firefox ESR < 140.8.
Discussion:
This issue has been addressed in the following products:
Red Hat Enterprise Linux 8
Via RHSA-2026:3338 https://access.redhat.com/errata/RHSA-2026:3338
---
This issue has been addressed in the following products:
Red Hat Enterprise Linux 9
Via RHSA-2026:3339 https://access.redhat.com/errata/RHSA-2026:3339
---
This issue has been addressed in the following products:
Red Hat Enterprise Linux 10
Via RHSA-2026:3361 https://access.redhat.com/errata/RHSA-2026:3361
---
This issue has been addressed in the following products:
Red Hat Enterprise
Wiz
CVE-2026-2761 Impact, Exploitability, and Mitigation Steps | Wiz
blogs_wiz·CVSS 10.0
CVE-2026-2761 [CRITICAL] CVE-2026-2761 Impact, Exploitability, and Mitigation Steps | Wiz
## CVE-2026-2761 :
NixOS vulnerability analysis and mitigation
Sandbox escape in the Graphics: WebRender component. This vulnerability affects Firefox < 148, Firefox ESR < 115.33, Firefox ESR < 140.8, Thunderbird < 148, and Thunderbird < 140.8.
Source : NVD
## 10
Score
Published February 24, 2026
Severity CRITICAL
CNA Score 10.0
Affected Technologies
NixOS
Mozilla Firefox
Has Public Exploit No
Has CISA KEV Exploit No
CISA KEV Release Date N/A
CISA KEV Due Date N/A
Exploitation Probability Percentile (EPSS) 34
Exploitation Probability (EPSS) 0.1
Affected packages and libraries
cpe:2.3:a:mozilla:firefox
cpe:2.3:a:mozilla:thunderbird
Sources
AlmaLinux 8 Severity HIGH Has Fix Added at: Mar 03, 2026
AlmaLinux 9 Severity HIGH Has Fix Added at: Mar 02, 2026
Debian 11, 12
https://bugzilla.mozilla.org/show_bug.cgi?id=2011063https://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/errata/RHSA-2026:3338https://access.redhat.com/errata/RHSA-2026:3339https://access.redhat.com/errata/RHSA-2026:3361https://access.redhat.com/errata/RHSA-2026:3491https://access.redhat.com/errata/RHSA-2026:3492https://access.redhat.com/errata/RHSA-2026:3493https://access.redhat.com/errata/RHSA-2026:3494https://access.redhat.com/errata/RHSA-2026:3495https://access.redhat.com/errata/RHSA-2026:3496https://access.redhat.com/errata/RHSA-2026:3497https://access.redhat.com/errata/RHSA-2026:3515https://access.redhat.com/errata/RHSA-2026:3516https://access.redhat.com/errata/RHSA-2026:3517https://access.redhat.com/errata/RHSA-2026:3976https://access.redhat.com/errata/RHSA-2026:3978https://access.redhat.com/errata/RHSA-2026:3979https://access.redhat.com/errata/RHSA-2026:3980https://access.redhat.com/errata/RHSA-2026:3981https://access.redhat.com/errata/RHSA-2026:3982https://access.redhat.com/errata/RHSA-2026:3983https://access.redhat.com/errata/RHSA-2026:3984https://access.redhat.com/errata/RHSA-2026:4022https://access.redhat.com/errata/RHSA-2026:4152https://access.redhat.com/errata/RHSA-2026:4260https://access.redhat.com/errata/RHSA-2026:4432https://access.redhat.com/security/cve/CVE-2026-2761https://bugzilla.redhat.com/show_bug.cgi?id=2442309https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-2761.json
2026-02-24
Published