CVE-2026-90399 — Kernel
HIGHCVE-2026-90399 is a high-severity (CVSS 8.4) vulnerability in Kernel. A fix is available for Kernel — see the affected versions and patch details below.
wifi: ath12k: fix stride mismatch in mac_phy_caps_parse()
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
How urgent is this, really
CVE-2026-90399 plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.
Where this sits among everything scored
Of 374,847 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
Real-World Exposure
KernelReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Linux packages — download data is not available via public APIs for these ecosystems.
Description
In the Linux kernel, the following vulnerability has been resolved:
wifi: ath12k: fix stride mismatch in mac_phy_caps_parse()
Currently, in ath12k_wmi_mac_phy_caps_parse(), kzalloc() sizes the mac_phy_caps buffer as tot_phy_id * len, where len is clamped to min(firmware_len, sizeof(struct ath12k_wmi_mac_phy_caps_params)). The subsequent memcpy() destination advances by sizeof(full struct) per slot via C pointer arithmetic, not by the clamped len. When firmware sends short TLVs, the second and later slots are written past the end of the allocation.
The reader in ath12k_pull_mac_phy_cap_svc_ready_ext() also indexes the buffer with full-struct pointer arithmetic, so the allocation must match that stride.
Fix by using kzalloc_objs(), which derives the element size from the pointer type, making allocation size and pointer stride provably consistent regardless of what len the firmware provides.
Tested-on: WCN7850 hw2.0 PCI WLAN.HMT.1.1.c7-00108-QCAHMTSWPL_V1.0_V2.0_SILICONZ_UPSTREAM-3
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐧Linux | Kernel | ≥ 6.3.0&&< 6.12.110 | 6.12.110 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for Kernel, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update Kernel to 6.12.110 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-90399 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2026-90399 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2026-90399. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2026-90399 in your dependencies?
O3 Security finds CVE-2026-90399 across Linux dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.