CVE-2026-72287
HIGHCVE-2026-72287 is a high-severity (CVSS 7.8) vulnerability in Kernel. O3 Security confirms whether CVE-2026-72287 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
KVM: nVMX: Move vTPR vs. TPR Threshold consistency check into "normal" checks
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:
KVM: nVMX: Move vTPR vs. TPR Threshold consistency check into "normal" checks
Move the off-by-default consistency check for vmcs12.tpr_threshold vs. the virtual APIC vTPR into the "normal" controls checks, as waiting until KVM has loaded some amount of state is unnecessary and actively dangerous. Specifically, failure to unwind vmcs01.GUEST_CR3 to KVM's value when EPT is disabled results in KVM running L1 with an L1-controlled CR3, not with KVM's CR3!
Alternatively, KVM could simply reset the MMU to force a reload of vmcs01.GUEST_CR3, but the only reason the check was shoved into a "late" flow was to wait until the vmcs12 pages were retrieved. Rather than build up more crusty code, simply access vTPR using a regular guest memory access (performance isn't a concern). To circumvent the restrictions that led to KVM deferring nested_get_vmcs12_pages(), (a) use a VM-scoped API to read guest memory so that it always hits non-SMM memslots (for RSM), and (b) skip the check (since its off-by-default anyways) when the vCPU doesn't want to run, i.e. when userspace is restoring/stuffing state.
If reading guest memory fails, simply skip the consistency check, as KVM's de facto ABI is that VMX instruction accesses to non-existent memory get PCI Bus Error semantics, where reads return 0xFFs. And if vTPR=0xFF, then the vTPR is guaranteed to be greater than or equal to TPR_THRESHOLD.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐧Linux | Kernel | ≥ 6.19.0&&< 7.1.5 | 7.1.5 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for Kernel. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update Kernel to 7.1.5 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-72287 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 pinpoints whether CVE-2026-72287 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to CVE-2026-72287. 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-2026-72287 in your dependencies?
O3 detects CVE-2026-72287 across Linux dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.