CVE-2025-39954
Linux Kernel 6.15 – 6.16.9
Raw vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:HSummary
CVE-2025-39954 is a medium-severity Divide By Zero (CWE-369) vulnerability in Linux Linux Kernel. Its CVSS base score is 5.5 (Medium).
Operationally, ranked at the 2th 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 SI-2 (Flaw Remediation) — see the control section below for these in your framework.
OWASP Top 10 for Web (2025)
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2025-33329
Vulnerability Data
In the Linux kernel, the following vulnerability has been resolved: clk: sunxi-ng: mp: Fix dual-divider clock rate readback When dual-divider clock support was introduced, the P divider offset was left out of the .recalc_rate readback function. This causes the clock…
more
rate to become bogus or even zero (possibly due to the P divider being 1, leading to a divide-by-zero). Fix this by incorporating the P divider offset into the calculation.
- CWE(s)
Related Threats
CVEs Like This One
Affected Assets
Mitigating Controls
Control response
Mitigating Controls (NIST 800-53 r5) AI
Rigorous developer testing of .recalc_rate paths for dual-divider clocks would have exercised P-divider values and caught the missing offset before release.
Secure development standards requiring review of all fields added to clock structures would have identified the incomplete dual-divider implementation.
Prompt application of the published kernel patch directly eliminates the divide-by-zero condition described in the CVE.
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 include code analysis, input validation, and testing that prevent divide-by-zero errors.
Vulnerability identification processes can discover divide-by-zero flaws via static analysis or testing.
Routine patching and replacement can remediate divide-by-zero bugs present in deployed software.
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 in development can detect divide-by-zero conditions before release.
Secure development lifecycle includes input validation and error-handling practices that can prevent divide-by-zero faults.
Application security requirements can mandate checks for zero denominators and safe arithmetic handling.
Secure architecture principles encourage defensive coding patterns that avoid arithmetic exceptions.
Secure coding standards directly require validation to prevent divide-by-zero and similar runtime faults.