CVE-2026-4710
Published: 24 March 2026
Summary
CVE-2026-4710 is a critical-severity Improper Restriction of Operations within the Bounds of a Memory Buffer (CWE-119) vulnerability in Mozilla Firefox. Its CVSS base score is 9.8 (Critical).
Operationally, exploitation aligns with the MITRE ATT&CK technique Exploitation for Client Execution (T1203); ranked at the 7.1th 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-16 (Memory Protection) and SI-2 (Flaw Remediation).
Threat & Defense at a Glance
Threat & Defense Details
Mitigating Controls (NIST 800-53 r5)AI
Requires timely identification, reporting, and correction of system flaws, directly mandating patching of this critical buffer overflow vulnerability in Firefox and Thunderbird.
Implements memory protection mechanisms like ASLR, DEP, and stack canaries that directly mitigate exploitation of buffer overflow vulnerabilities such as CVE-2026-4710.
Mandates validation of information inputs to the Audio/Video component, addressing improper boundary conditions that enable the buffer overflow.
MITRE ATT&CK Enterprise TechniquesAI
Why these techniques?
Remote memory corruption (CWE-119) in client application (Firefox/Thunderbird A/V component) directly enables arbitrary code execution with no user interaction or privileges, mapping to Exploitation for Client Execution.
NVD Description
Incorrect boundary conditions in the Audio/Video component. This vulnerability was fixed in Firefox 149, Firefox ESR 140.9, Thunderbird 149, and Thunderbird 140.9.
Deeper analysisAI
CVE-2026-4710 involves incorrect boundary conditions in the Audio/Video component of Mozilla products, including Firefox and Thunderbird. This vulnerability, classified under CWE-119 (Improper Restriction of Operations within the Bounds of a Memory Buffer) and NVD-CWE-noinfo, was addressed in Firefox 149, Firefox ESR 140.9, Thunderbird 149, and Thunderbird 140.9. It carries a CVSS v3.1 base score of 9.8, reflecting its critical severity, and was published on 2026-03-24.
The vulnerability enables remote exploitation over the network (AV:N) with low attack complexity (AC:L), requiring no privileges (PR:N) or user interaction (UI:N), and without changing scope (S:U). Attackers can achieve high impacts on confidentiality, integrity, and availability (C:H/I:H/A:H), potentially leading to arbitrary code execution, data compromise, or system disruption on affected systems.
Mozilla's security advisories (MFSA2026-20, MFSA2026-22, MFSA2026-23, MFSA2026-24) and Bugzilla entry (bug 2016370) confirm the issue and recommend updating to the fixed versions—Firefox 149, Firefox ESR 140.9, Thunderbird 149, or Thunderbird 140.9—as the primary mitigation. No additional workarounds are specified in the provided references.
Details
- CWE(s)