CVE-2026-4715
Mozilla Firefox ≤ 140.9.0
Raw vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:HCVSS and EPSS are reproduced from their sources (NVD, FIRST EPSS). Risk Priority is our own derived reading, not an NVD score.
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 OS Credential Dumping (T1003); ranked at the 36th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.
The strongest mitigations our analysis identified map to SA-11 (Developer Testing and Evaluation) and SA-15 (Development Process, Standards, and Tools) — see the control section below for these in your framework.
Deeper analysis AI-assisted summary
Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.
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.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-14845
Vulnerability Data
Uninitialized memory in the Graphics: Canvas2D component. This vulnerability was fixed in Firefox 149, Firefox ESR 140.9, Thunderbird 149, and Thunderbird 140.9.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise Techniques
CVEs Like This One
Affected Assets
Mitigating Controls
Mitigating Controls (NIST 800-53 r5) AI
Developer testing and evaluation (including static analysis) can find uses of uninitialized resources after they are coded.
Requiring documented development standards and tools can mandate initialization checks and safe patterns that stop the weakness from being introduced.
Engineering principles can require explicit resource initialization before use, structurally avoiding uninitialized access.
Mitigating Controls (NIST CSF 2.0) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.
Secure SDLC activities such as static analysis and code review directly prevent use of uninitialized resources while also addressing many other weaknesses.
Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.