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3 stories in the last 30d

Xen Security Advisory 511 v3 (CVE-2026-79603) - Unconditionally do TLB flushing ahead of page scrubbing

Xen Project released XSA-511 (CVE-2026-79603) fixing missing TLB flushes before page scrubbing that can leak x86 PV guest data.

Xen Security Advisory 511 v3 publicly discloses CVE-2026-79603, a TLB handling flaw in the Xen hypervisor on x86. x86 PV guests can free memory pages while a stale TLB entry still points to them, and Xen only flushes the TLB when the page is reused, potentially exposing stale data ahead of scrubbing. The advisory changes Xen to unconditionally flush the TLB ahead of page scrubbing. The issue was published in version 3 of the advisory.

USN-8726-1: Linux kernel vulnerabilities

Ubuntu issued kernel security update USN-8726-1 fixing an Arm TLB invalidation flaw (CVE-2025-10263) that enables local privilege escalation, plus other kernel fixes.

Ubuntu released USN-8726-1, a security update for the generic Linux kernel. It fixes CVE-2025-10263, where certain Arm processors complete broadcast TLB invalidation before related memory writes are globally observed, potentially letting local attackers bypass memory protections or escalate privileges. The update also addresses additional kernel flaws in ARM64, ARM32, RISC-V, S390 and other subsystems.

Ubuntu Security Noticesupdated · 9d agofirst · 9d agoAdvisory 6 sourcesCVE-2025-10263

CVE-2026-89775: Guest-to-Host Escape in KVM/arm64

Disclosed CVE-2026-89775 lets a guest VM escape to the host on KVM/arm64 systems with nested virtualization enabled.

Researcher Hyunwoo Kim disclosed CVE-2026-89775, a guest-to-host escape in KVM/arm64, after the embargo agreed with linux-distros maintainers expired. The root cause is a type truncation of the stage-1 walk level that makes a size computation return 0, the value meaning 'size unknown'. The VNCR pseudo-TLB invalidation path then interprets that 0 as a valid value on ARM64 hosts where nested virtualization is enabled.

oss-security · 11h agoVulnerabilityCVE-2026-89775