CVE-2026-4715
Published: 24 March 2026
Summary
CVE-2026-4715 is a critical-severity Use of Uninitialized Resource (CWE-908) vulnerability in Mozilla Firefox. Its CVSS base score is 9.1 (Critical).
Operationally, exploitation aligns with the MITRE ATT&CK technique Drive-by Compromise (T1189); 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-2 (Flaw Remediation) and RA-5 (Vulnerability Monitoring and Scanning).
Threat & Defense at a Glance
Threat & Defense Details
Mitigating Controls (NIST 800-53 r5)AI
Mandates timely patching of software flaws like the uninitialized memory vulnerability in Firefox Canvas2D to eliminate exploitability.
Requires scanning for vulnerabilities such as CVE-2026-4715 in browser components and initiating remediation to affected systems.
Provides memory protection mechanisms that mitigate unauthorized disclosure or crashes from uninitialized memory exploitation.
MITRE ATT&CK Enterprise TechniquesAI
Why these techniques?
Uninitialized memory read in client-side Canvas2D rendering enables remote exploitation via malicious web content or email (Drive-by Compromise) and direct browser crashes for DoS (Application or System Exploitation).
NVD Description
Uninitialized memory in the Graphics: Canvas2D component. This vulnerability was fixed in Firefox 149, Firefox ESR 140.9, Thunderbird 149, and Thunderbird 140.9.
Deeper analysisAI
CVE-2026-4715 is an uninitialized memory vulnerability (CWE-908) in the Graphics: Canvas2D component of Mozilla products. It affects Firefox versions prior to 149, Firefox ESR versions prior to 140.9, Thunderbird versions prior to 149, and Thunderbird versions prior to 140.9. The vulnerability was publicly disclosed on 2026-03-24 and carries a CVSS v3.1 base score of 9.1, indicating critical severity.
Remote attackers can exploit this vulnerability over the network with low complexity, requiring no privileges, no user interaction, and without changing the scope of impact. Successful exploitation enables high confidentiality and availability impacts, such as unauthorized disclosure of sensitive information from uninitialized memory or denial-of-service via crashes, without affecting integrity.
Mozilla security advisories (MFSA 2026-20, 22, 23, 24) and the associated Bugzilla entry (bug 2018405) detail the patch, recommending immediate updates to Firefox 149, Firefox ESR 140.9, Thunderbird 149, or Thunderbird 140.9 to mitigate the issue. No workarounds are specified in the provided references.
Details
- CWE(s)