CVE-2026-2806
Mozilla Firefox ≤ 148.0
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-2026-2806 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 Junk Data (T1001.001); ranked at the 46th 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-2026-2806 is a critical vulnerability involving uninitialized memory in the Graphics: Text component, affecting Mozilla Firefox and Thunderbird. Assigned CWE-908 (Use of Uninitialized Resource) and CWE-457 (Use of Uninitialized Variable), it received a CVSS v3.1 base score of 9.1, reflecting its high severity due to network accessibility, low attack complexity, and no requirements for privileges or user interaction.
A remote, unauthenticated attacker can exploit this vulnerability over the network with low complexity and no user interaction. Successful exploitation enables high-impact confidentiality violations, such as disclosure of sensitive information from uninitialized memory, alongside high-impact availability disruptions, potentially leading to denial-of-service conditions like application crashes.
Mozilla addressed the issue in Firefox version 148 and Thunderbird version 148, as detailed in security advisories MFSA 2026-13 and MFSA 2026-16, along with the upstream bug report at Bugzilla ID 2006199. Security practitioners should ensure affected systems are updated to these patched versions to mitigate the risk.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-8459
Vulnerability Data
Uninitialized memory in the Graphics: Text component. This vulnerability was fixed in Firefox 148 and Thunderbird 148.
- 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.