CVE-2026-0880
Published: 13 January 2026
Summary
CVE-2026-0880 is a high-severity Integer Overflow or Wraparound (CWE-190) vulnerability in Mozilla Firefox. Its CVSS base score is 8.8 (High).
Operationally, exploitation aligns with the MITRE ATT&CK technique Exploitation for Privilege Escalation (T1068); ranked at the 36.3th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.
The strongest mitigations our analysis identified are NIST 800-53 SI-2 (Flaw Remediation) and RA-5 (Vulnerability Monitoring and Scanning).
Deeper analysis
CVE-2026-0880 is a sandbox escape vulnerability stemming from an integer overflow (CWE-190) in the Graphics component of Mozilla products. It affects Firefox versions prior to 147, Firefox ESR versions prior to 115.32 and 140.7, Thunderbird versions prior to 147 and 140.7. The issue was publicly disclosed on January 13, 2026, and carries a CVSS v3.1 base score of 8.8 (AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H), indicating high severity due to its potential for significant impact.
The vulnerability can be exploited remotely by an unauthenticated attacker with low complexity, requiring only user interaction such as loading a malicious webpage or file that triggers graphics processing. Successful exploitation enables sandbox escape, granting the attacker high-level access to confidentiality, integrity, and availability within the browser's scope, potentially allowing arbitrary code execution or data access confined to the sandboxed environment.
Mozilla's security advisories (MFSA 2026-01 through 2026-04) and the associated Bugzilla entry (bug 2005014) detail the fix applied in the listed versions. Security practitioners should prioritize updating affected Firefox and Thunderbird installations to the patched releases to mitigate the risk, as no workarounds are specified in the provided references.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-2086
Vulnerability details
Sandbox escape due to integer overflow 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.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise TechniquesAI
Why these techniques?
Sandbox escape via remote browser graphics exploit (malicious page/file) directly enables drive-by compromise (T1189), client-side exploitation for execution (T1203), and privilege escalation (T1068).
CVEs Like This One
Affected Assets
Mitigating Controls
Mitigating Controls (NIST 800-53 r5) AI
Mandates timely remediation of known software flaws like the integer overflow in Firefox's Graphics component to prevent sandbox escape.
Requires organizations to receive and act on vendor security advisories like Mozilla MFSA 2026-01 for patching affected Firefox and Thunderbird versions.
Enables vulnerability scanning to identify systems with unpatched Firefox or Thunderbird versions vulnerable to this sandbox escape.