CVE-2026-0879
published 2026-01-13CVE-2026-0879: Sandbox escape due to incorrect boundary conditions in the Graphics component. This vulnerability was fixed in Firefox 147, Firefox ESR 115.32, Firefox ESR…
PriorityP349critical9.8CVSS 3.1
AVNACLPRNUINSUCHIHAH
EPSS
0.53%
41.0th percentile
Sandbox escape due to incorrect boundary conditions in the Graphics component. This vulnerability was fixed in Firefox 147, Firefox ESR 115.32, Firefox ESR 140.7, Thunderbird 147, and Thunderbird 140.7.
Affected
13 ranges
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| debian | firefox | < firefox 147.0-1 (sid) | firefox 147.0-1 (sid) |
| debian | firefox-esr | < firefox 147.0-1 (sid) | firefox 147.0-1 (sid) |
| debian | thunderbird | < firefox 147.0-1 (sid) | firefox 147.0-1 (sid) |
| mozilla | firefox | < 115.32.0 | 115.32.0 |
| mozilla | firefox | < 147.0 | 147.0 |
| mozilla | firefox | — | — |
| mozilla | firefox | >= 128.0 < 140.7.0 | 140.7.0 |
| mozilla | thunderbird | < 140.7.0 | 140.7.0 |
| mozilla | thunderbird | < 147.0 | 147.0 |
| mozilla | thunderbird | >= 0 < 1:140.7.0esr-1~deb11u1 | 1:140.7.0esr-1~deb11u1 |
| mozilla | thunderbird | >= 0 < 1:140.7.0esr-1~deb12u1 | 1:140.7.0esr-1~deb12u1 |
| mozilla | thunderbird | >= 0 < 1:140.7.0esr-1~deb13u1 | 1:140.7.0esr-1~deb13u1 |
| mozilla | thunderbird | >= 0 < 1:140.7.0esr-1 | 1:140.7.0esr-1 |
CVSS provenance
nvdv3.19.8CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
osv9.8CRITICAL
vendor_debian9.8CRITICAL
vendor_redhat9.8CRITICAL
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Ubuntu
Thunderbird vulnerabilities
vendor_ubuntu·2026-02-02
CVE-2025-8031 Thunderbird vulnerabilities
Title: Thunderbird vulnerabilities
Summary: Several security issues were fixed in Thunderbird.
Multiple security issues were discovered in Thunderbird. If a user were
tricked into opening a specially crafted website in a browsing context,
an attacker could potentially exploit these to cause a denial of service,
obtain sensitive information, bypass security restrictions, cross-site
tracing, or execute arbitrary code.
Instructions: In general, a standard system update will make all the necessary changes.
Red Hat
firefox: thunderbird: Sandbox escape due to incorrect boundary conditions in the Graphics component
vendor_redhat·2026-01-13·CVSS 9.8
CVE-2026-0879 [CRITICAL] firefox: thunderbird: Sandbox escape due to incorrect boundary conditions in the Graphics component
firefox: thunderbird: Sandbox escape due to incorrect boundary conditions in the Graphics component
Sandbox escape due to incorrect boundary conditions in the Graphics component. This vulnerability affects Firefox < 147, Firefox ESR < 115.32, Firefox ESR < 140.7, Thunderbird < 147, and Thunderbird < 140.7.
A flaw was found in Firefox and Thunderbird. The Mozilla Foundation's Security Advisory describes the following issue:
Sandbox escape due to incorrect boundary conditions in the Graphics 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: fir
Debian
CVE-2026-0879: firefox - Sandbox escape due to incorrect boundary conditions in the Graphics component. T...
vendor_debian·2026·CVSS 9.8
CVE-2026-0879 [CRITICAL] CVE-2026-0879: firefox - Sandbox escape due to incorrect boundary conditions in the Graphics component. T...
Sandbox escape due to incorrect boundary conditions in the Graphics component. This vulnerability affects Firefox < 147, Firefox ESR < 115.32, Firefox ESR < 140.7, Thunderbird < 147, and Thunderbird < 140.7.
Scope: local
sid: resolved (fixed in 147.0-1)
Mozilla
Mozilla Foundation Security Advisory 2026-01: CVE-2026-0879
vendor_mozilla·CVSS 9.8
CVE-2026-0879 [CRITICAL] Mozilla Foundation Security Advisory 2026-01: CVE-2026-0879
Mozilla Foundation Security Advisory 2026-01
CVE: CVE-2026-0879
Product: Firefox
Impact: moderate
Fixed in: Firefox 147
Mozilla
Mozilla Foundation Security Advisory 2026-02: CVE-2026-0879
vendor_mozilla·CVSS 9.8
CVE-2026-0879 [CRITICAL] Mozilla Foundation Security Advisory 2026-02: CVE-2026-0879
Mozilla Foundation Security Advisory 2026-02
CVE: CVE-2026-0879
Product: Firefox ESR
Impact: moderate
Fixed in: Firefox ESR 115.32
Mozilla
Mozilla Foundation Security Advisory 2026-05: CVE-2026-0879
vendor_mozilla·CVSS 9.8
CVE-2026-0879 [CRITICAL] Mozilla Foundation Security Advisory 2026-05: CVE-2026-0879
Mozilla Foundation Security Advisory 2026-05
CVE: CVE-2026-0879
Product: Thunderbird
Impact: high
Fixed in: Thunderbird 140.7
Mozilla
Mozilla Foundation Security Advisory 2026-03: CVE-2026-0879
vendor_mozilla·CVSS 9.8
CVE-2026-0879 [CRITICAL] Mozilla Foundation Security Advisory 2026-03: CVE-2026-0879
Mozilla Foundation Security Advisory 2026-03
CVE: CVE-2026-0879
Product: Firefox ESR
Impact: high
Fixed in: Firefox ESR 140.7
Mozilla
Mozilla Foundation Security Advisory 2026-04: CVE-2026-0879
vendor_mozilla·CVSS 9.8
CVE-2026-0879 [CRITICAL] Mozilla Foundation Security Advisory 2026-04: CVE-2026-0879
Mozilla Foundation Security Advisory 2026-04
CVE: CVE-2026-0879
Product: Thunderbird
Impact: moderate
Fixed in: Thunderbird 147
OSV
CVE-2026-0879: Sandbox escape due to incorrect boundary conditions in the Graphics component
osv·2026-01-13·CVSS 9.8
CVE-2026-0879 [CRITICAL] CVE-2026-0879: Sandbox escape due to incorrect boundary conditions in the Graphics component
Sandbox escape due to incorrect boundary conditions in the Graphics component. This vulnerability affects Firefox < 147, Firefox ESR < 115.32, Firefox ESR < 140.7, Thunderbird < 147, and Thunderbird < 140.7.
GHSA
GHSA-r38v-527h-36cj: Sandbox escape due to incorrect boundary conditions in the Graphics component
ghsa_unreviewed·2026-01-13
CVE-2026-0879 [CRITICAL] CWE-119 GHSA-r38v-527h-36cj: Sandbox escape due to incorrect boundary conditions in the Graphics component
Sandbox escape due to incorrect boundary conditions in the Graphics component. This vulnerability affects Firefox < 147, Firefox ESR < 115.32, and Firefox ESR < 140.7.
No detection rules found.
No public exploits indexed.
Wiz
CVE-2026-0879 Impact, Exploitability, and Mitigation Steps | Wiz
blogs_wiz·CVSS 9.8
CVE-2026-0879 [CRITICAL] CVE-2026-0879 Impact, Exploitability, and Mitigation Steps | Wiz
## CVE-2026-0879 :
NixOS vulnerability analysis and mitigation
Sandbox escape due to incorrect boundary conditions in the Graphics component. This vulnerability affects Firefox < 147, Firefox ESR < 115.32, Firefox ESR < 140.7, Thunderbird < 147, and Thunderbird < 140.7.
Source : NVD
## 9.8
Score
Published January 13, 2026
Severity CRITICAL
CNA Score 9.8
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) 7.3
Exploitation Probability (EPSS) N/A
Affected packages and libraries
rhel10::thunderbird-flatpak
MozillaThunderbird-openpgp-librnp
Sources
AlmaLinux 8 Severity HIGH Has Fix Added at: Feb 11, 2026
AlmaLinux 9 Severity HIGH Has Fix Added
Bugzilla
CVE-2026-0879 firefox: thunderbird: Sandbox escape due to incorrect boundary conditions in the Graphics component
bugzilla·2026-01-13·CVSS 9.8
CVE-2026-0879 [CRITICAL] CVE-2026-0879 firefox: thunderbird: Sandbox escape due to incorrect boundary conditions in the Graphics component
CVE-2026-0879 firefox: thunderbird: Sandbox escape due to incorrect boundary conditions in the Graphics component
Sandbox escape due to incorrect boundary conditions in the Graphics component. This vulnerability affects Firefox < 147, Firefox ESR < 115.32, and Firefox ESR < 140.7.
Discussion:
This issue has been addressed in the following products:
Red Hat Enterprise Linux 8
Via RHSA-2026:0667 https://access.redhat.com/errata/RHSA-2026:0667
---
This issue has been addressed in the following products:
Red Hat Enterprise Linux 9
Via RHSA-2026:0694 https://access.redhat.com/errata/RHSA-2026:0694
---
This issue has been addressed in the following products:
Red Hat Enterprise Linux 9
Via RHSA-2026:0924 https://access.redhat.com/errata/RHSA-2026:0924
---
This issue has been addres
https://bugzilla.mozilla.org/show_bug.cgi?id=2004602https://www.mozilla.org/security/advisories/mfsa2026-01/https://www.mozilla.org/security/advisories/mfsa2026-02/https://www.mozilla.org/security/advisories/mfsa2026-03/https://www.mozilla.org/security/advisories/mfsa2026-04/https://www.mozilla.org/security/advisories/mfsa2026-05/https://access.redhat.com/errata/RHSA-2026:0667https://access.redhat.com/errata/RHSA-2026:0694https://access.redhat.com/errata/RHSA-2026:0924https://access.redhat.com/errata/RHSA-2026:1320https://access.redhat.com/errata/RHSA-2026:1413https://access.redhat.com/errata/RHSA-2026:1414https://access.redhat.com/errata/RHSA-2026:1415https://access.redhat.com/errata/RHSA-2026:1461https://access.redhat.com/errata/RHSA-2026:1462https://access.redhat.com/errata/RHSA-2026:1471https://access.redhat.com/errata/RHSA-2026:1487https://access.redhat.com/errata/RHSA-2026:2041https://access.redhat.com/errata/RHSA-2026:2043https://access.redhat.com/errata/RHSA-2026:2044https://access.redhat.com/errata/RHSA-2026:2047https://access.redhat.com/errata/RHSA-2026:2069https://access.redhat.com/errata/RHSA-2026:2070https://access.redhat.com/errata/RHSA-2026:2073https://access.redhat.com/errata/RHSA-2026:2074https://access.redhat.com/errata/RHSA-2026:2220https://access.redhat.com/errata/RHSA-2026:2231https://access.redhat.com/errata/RHSA-2026:2271https://access.redhat.com/errata/RHSA-2026:2286https://access.redhat.com/security/cve/CVE-2026-0879https://bugzilla.redhat.com/show_bug.cgi?id=2428973https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-0879.json
2026-01-13
Published