CVE-2026-0882
Published: 13 January 2026
Summary
CVE-2026-0882 is a high-severity Use After Free (CWE-416) vulnerability in Mozilla Firefox. Its CVSS base score is 8.8 (High).
Operationally, exploitation aligns with the MITRE ATT&CK technique Drive-by Compromise (T1189); ranked at the 5.9th 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 RA-5 (Vulnerability Monitoring and Scanning) and SI-2 (Flaw Remediation).
Threat & Defense at a Glance
Threat & Defense Details
Mitigating Controls (NIST 800-53 r5)AI
Directly requires timely identification, reporting, and remediation of software flaws like this use-after-free vulnerability through patching to fixed versions such as Firefox 147.
Mandates vulnerability scanning and monitoring to identify instances of CVE-2026-0882 in deployed Firefox and Thunderbird versions for prioritized patching.
Implements memory protections such as ASLR and DEP that mitigate exploitation of use-after-free vulnerabilities in the IPC component.
MITRE ATT&CK Enterprise TechniquesAI
Why these techniques?
Use-after-free RCE in browser IPC component directly enables client-side exploitation via drive-by or user-executed malicious content.
NVD Description
Use-after-free in the IPC component. This vulnerability was fixed in Firefox 147, Firefox ESR 115.32, Firefox ESR 140.7, Thunderbird 147, and Thunderbird 140.7.
Deeper analysisAI
CVE-2026-0882 is a use-after-free vulnerability (CWE-416) in the IPC component of Mozilla Firefox and Thunderbird. It affects versions of Firefox prior to 147, Firefox ESR prior to 115.32 and 140.7, and Thunderbird prior to 147 and 140.7.
The vulnerability 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). A remote, unauthenticated attacker can exploit it over the network with low attack complexity, though it requires user interaction, potentially achieving high impacts on confidentiality, integrity, and availability within the affected browser scope.
Mozilla security advisories (MFSA 2026-01 through 2026-04) and Bugzilla entry 1924125 detail the fix applied in the listed versions. Mitigation involves updating to Firefox 147, Firefox ESR 115.32 or 140.7, Thunderbird 147, or Thunderbird 140.7.
Details
- CWE(s)