CVE-2026-0881
Sandbox escape in the Messaging System component
10.0 Critical
Sandbox escape in the Messaging System component. This vulnerability was fixed in Firefox 147 and Thunderbird 147.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- High
- Integrity
- High
- Availability
- High
Exploit likelihood
0.35%Up 0.3 points since Jan 14, 2026
What each source reports
CVE List Score used
Sandbox escape in the Messaging System component
Sandbox escape in the Messaging System component. This vulnerability was fixed in Firefox 147 and Thunderbird 147.
- Record
CVE-2026-0881- CVSS 3.1
- 10.0 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H - CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H - Weakness
- CWE-693, CWE-284
- Updated
- 2026-11-02
EUVDEUVD-2026-2087
Sandbox escape in the Messaging System component. This vulnerability was fixed in Firefox 147 and Thunderbird 147.
- Record
EUVD-2026-2087- CVSS 3.1
- 10.0 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-cw2j-6pvw-7g9v
Sandbox escape in the Messaging System component. This vulnerability affects Firefox < 147.
Sandbox escape in the Messaging System component. This vulnerability affects Firefox < 147.
- Record
GHSA-cw2j-6pvw-7g9v- CVSS 3.1
- 10.0 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H - Weakness
- CWE-284
- Updated
- 2026-11-02
NVD
Sandbox escape in the Messaging System component. This vulnerability was fixed in Firefox 147 and Thunderbird 147.
- Record
CVE-2026-0881- CVSS 3.1
- 10.0 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H - CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H - Weakness
- CWE-284, CWE-693
- Updated
- 2026-11-02
OSVUBUNTU-CVE-2026-0881
Sandbox escape in the Messaging System component. This vulnerability affects Firefox < 147 and Thunderbird < 147.
- Record
UBUNTU-CVE-2026-0881- CVSS 3.1
- 10.0 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H - Updated
- 2026-11-02
OSVopenSUSE-SU-2026:10046-1 No score
MozillaFirefox-147.0-1.1 on GA media
These are all security issues fixed in the MozillaFirefox-147.0-1.1 package on the GA media of openSUSE Tumbleweed.
- Record
openSUSE-SU-2026:10046-1- Updated
- 2026-11-02
OSVopenSUSE-SU-2026:11373-1 No score
firefox-esr-153.0-1.1 on GA media
These are all security issues fixed in the firefox-esr-153.0-1.1 package on the GA media of openSUSE Tumbleweed.
- Record
openSUSE-SU-2026:11373-1- Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
MozillaFirefoxopenSUSE:Tumbleweed From an advisory covering 16 CVEs |
before 147.0-1.1 | 147.0-1.1 |
firefox-esropenSUSE:Tumbleweed From an advisory covering 228 CVEs |
before 153.0-1.1 | 153.0-1.1 |
History
| Recorded | Changed | Sources |
|---|---|---|
| affected, facts | ||
| affected | ||
| first indexed | CVE List, EUVD, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-0881 is a critical vulnerability (CVSS 10.0) in Mozilla Firefox, published January 13, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.35%, the 28th percentile. No source names a fixed version.
References
bugzilla.mozilla.org/show_bug.cgi?id=2005845
mozilla.org/security/advisories/mfsa2026-01
access.redhat.com/security/cve/CVE-2026-0881
bugzilla.redhat.com/show_bug.cgi?id=2428970
security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-0881.json
Show 194 moreShow less
nvd.nist.gov/vuln/detail/CVE-2026-0881
github.com/advisories/GHSA-cw2j-6pvw-7g9v
ubuntu.com/security/CVE-2026-0881
cve.org/CVERecord?id=CVE-2026-0881
suse.com/security/cve/CVE-2026-0877
This page doesn't list everything
Left out here: 51 references. The JSON record has them.