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ITScape

IdentifiersCVE-2026-46316CWE-416

CVE-2026-46316, dubbed ITScape, is a guest-to-host escape vulnerability in the Linux kernel's KVM/arm64 vGIC-ITS emulation. The bug is in vgic_its_invalidate_cache(), which walks the per-ITS translation cache with xa_for_each() and drops references with vgic_put_irq(). Due to incorrect handling during concurrent cache invalidation, the code can drop the iterated pointer rather than only the entry actually removed by xa_erase(). Because xa_erase() is atomic and multiple invalidation paths can run concurrently under different locking contexts, the same cache-held reference can be dropped more than once. This creates a double-put condition that can free an IRQ translation entry while it is still mapped by an ITE, resulting in a use-after-free in in-kernel KVM on arm64. Public reporting and PoC material indicate this can be driven from the guest side and can be exploited for guest escape to host kernel code execution.

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ANALYST BRIEF

Impact, mitigation & remediation

What it means. What to do now. Patch path, mitigations, and the assume-compromise checklist.

Impact

What an attacker gets, and what they’ve been doing with it.

Successful exploitation can break guest/host isolation in KVM/arm64 environments. Public disclosure and PoC reporting indicate that an untrusted guest VM can escalate from guest control to execution of commands on the host with kernel privileges, i.e., full host compromise from the guest context. At minimum, the flaw enables memory corruption and kernel instability due to the use-after-free; in the demonstrated case, it provides guest-to-host escape with root-level execution on the host. This is particularly severe for multi-tenant arm64 cloud environments running untrusted guests on unpatched hosts.

Mitigation

If you can’t patch tonight, do this now.

Until patched kernels are deployed, reduce exposure by preventing untrusted tenants or workloads from running on affected KVM/arm64 hosts, especially in multi-tenant environments. Restrict creation and execution of arm64 guest VMs on vulnerable hosts where possible, and avoid colocating mutually untrusted workloads. Because the issue is in in-kernel KVM rather than QEMU user-space emulation and can be triggered by guest-side actions, user-space hardening alone is not a sufficient mitigation. If operationally feasible, disable or avoid affected arm64 KVM virtualization paths until fixed kernels are installed.

Remediation

Patch, then assume compromise.

Apply the upstream Linux kernel fix that changes vgic_its_invalidate_cache() to drop the cache reference only for the entry actually returned by xa_erase(), ensuring each cache-held reference is released exactly once even under concurrent invalidation. The content identifies the mainline fix as commit 13031fb6b8357fbbcded2a7f4cba73e4781ee594. The disclosure also recommends applying related follow-on patches, including commit 70543358fa08e0f7cebc3447c3b70fe97ad7aaa8 (associated with CVE-2026-46317) and commit f2ca45b50d4216c9cc7ffabf50d9ad1932209251. Upgrade to a vendor kernel release that includes these fixes.
PUBLIC EXPLOITS

Exploits

No public exploits tracked yet. Mallory keeps watching.

VALID 0 / 0 TOTALView more in app

No public exploit code observed for this vulnerability.

EXPOSURE SURFACE

Affected products & vendors

Products and vendors Mallory has correlated with this vulnerability. Open in Mallory to drill down to specific CPE configurations and version ranges.

VendorProductType
LinuxLinux Kerneloperating_system

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What this page doesn’t show

The version that knows your environment.

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Exposure mapping

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Threat actor evidence

Every observed campaign linking this CVE to a named adversary.

Associated malware

Malware families riding this exploit, with evidence and IOCs.

Detection signatures

YARA, Sigma, Snort, and vendor rules, auto-deployed to your SIEM.

Vendor-by-vendor mapping

Cross-references every affected SKU, including bundled OEM variants.

Social activity7

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