CVE-2025-8027
Mozilla Firefox ≤ 115.26.0
Raw vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:NCVSS and EPSS are reproduced from their sources (NVD, FIRST EPSS). Risk Priority is our own derived reading, not an NVD score.
Summary
CVE-2025-8027 is a medium-severity Use of Uninitialized Variable (CWE-457) vulnerability in Mozilla Firefox. Its CVSS base score is 6.5 (Medium).
Operationally, ranked at the 28th 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.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2025-22372
Vulnerability Data
On 64-bit platforms IonMonkey-JIT only wrote 32 bits of the 64-bit return value space on the stack. Baseline-JIT, however, read the entire 64 bits. This vulnerability was fixed in Firefox 141, Firefox ESR 115.26, Firefox ESR 128.13, Firefox ESR 140.1,…
more
Thunderbird 141, Thunderbird 128.13, and Thunderbird 140.1.
- CWE(s)
Related Threats
CVEs Like This One
Affected Assets
Mitigating Controls
Mitigating Controls (NIST 800-53 r5) AI
Developer testing and static analysis directly find uses of uninitialized variables before deployment.
Documented development standards and tools can enforce initialization requirements in code.
Engineering principles can mandate explicit variable initialization to avoid uninitialized use.
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 practices directly catch uninitialized-variable defects via static analysis and code review while the control encompasses many additional development controls.
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.
Security testing can detect uninitialized-variable bugs, but the control is broader.
Secure development life cycle mandates practices that reduce uninitialized-variable defects.
Application security requirements can specify initialization rules, but the control itself does not directly address the weakness.
Secure coding explicitly requires variable initialization and static-analysis checks.