CVE-2026-89919
CVE-2026-89919 is a remote code execution vulnerability. O3 Security confirms whether CVE-2026-89919 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
In the Linux kernel, the following vulnerability has been resolved: KVM: s390: keyop: use mmu_lock to read gmap->asce Every other dat_* consumer in this file (kvm_s390_get_skeys, set_skeys,…
Description
In the Linux kernel, the following vulnerability has been resolved:
KVM: s390: keyop: use mmu_lock to read gmap->asce
Every other dat_* consumer in this file (kvm_s390_get_skeys, set_skeys, get_cmma_bits, set_cmma_bits, MEM_CLR_CMMA, kvm_s390_fixup_prefix, kvm_test_age_gfn, kvm_age_gfn) reads kvm->arch.gmap->asce inside the mmu_lock read-side. keyop is the only outlier.
gmap->asce is mutated under write_lock(mmu_lock) by gmap_set_limit() and keyop might use a stale asce value for walking as KVM_S390_KEYOP and KVM_S390_VM_MEM_LIMIT_SIZE can run concurrently. This can result in memory corruption.
Detection & mitigation playbook
VulnerabilityDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for the affected component. 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.
Remediation status
No patched version of the affected component has shipped for CVE-2026-89919 yet. Where your build allows, override or pin the dependency away from the vulnerable range, and apply any maintainer-recommended mitigation.
Mitigate without a patch
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-2026-89919 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-2026-89919. 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-2026-89919 in your dependencies?
O3 detects CVE-2026-89919 across dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.