The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available.

  - KVM: x86: Don't (re)check L1 intercepts when completing userspace I/O When completing emulation of     instruction that generated a userspace exit for I/O, don't recheck L1 intercepts as KVM has already     finished that phase of instruction execution, i.e. has already committed to allowing L2 to perform I/O. If     L1 (or host userspace) modifies the I/O permission bitmaps during the exit to userspace, KVM will treat     the access as being intercepted despite already having emulated the I/O access. Pivot on     EMULTYPE_NO_DECODE to detect that KVM is completing emulation. Of the three users of EMULTYPE_NO_DECODE,     only complete_emulated_io() (the intended recipient) can reach the code in question. gp_interception()'s     use is mutually exclusive with is_guest_mode(), and complete_emulated_insn_gp() unconditionally pairs     EMULTYPE_NO_DECODE with EMULTYPE_SKIP. The bad behavior was detected by a syzkaller program that toggles     port I/O interception during the userspace I/O exit, ultimately resulting in a WARN on     vcpu->arch.pio.count being non-zero due to KVM no completing emulation of the I/O instruction. WARNING:
    CPU: 23 PID: 1083 at arch/x86/kvm/x86.c:8039 emulator_pio_in_out+0x154/0x170 [kvm] Modules linked in:
    kvm_intel kvm irqbypass CPU: 23 UID: 1000 PID: 1083 Comm: repro Not tainted 6.16.0-rc5-c1610d2d66b1-next-     vm #74 NONE Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015 RIP:
    0010:emulator_pio_in_out+0x154/0x170 [kvm] PKRU: 55555554 Call Trace: <TASK> kvm_fast_pio+0xd6/0x1d0 [kvm]     vmx_handle_exit+0x149/0x610 [kvm_intel] kvm_arch_vcpu_ioctl_run+0xda8/0x1ac0 [kvm]     kvm_vcpu_ioctl+0x244/0x8c0 [kvm] __x64_sys_ioctl+0x8a/0xd0 do_syscall_64+0x5d/0xc60     entry_SYSCALL_64_after_hwframe+0x4b/0x53 </TASK> (CVE-2025-40026)

Note that Nessus relies on the presence of the package as reported by the vendor.

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Linux Distros Unpatched Vulnerability : CVE-2025-40026

high Nessus Plugin ID 271897

Version 1.40