CVE-2024-55881 | KVM: x86: Play nice with protected guests in complete_hypercall_exit()

In the Linux kernel, the following vulnerability has been resolved: KVM: x86: Play nice with protected guests in complete_hypercall_exit() Use is_64_bit_hypercall() instead of is_64_bit_mode() to detect a 64-bit hypercall when completing said hypercall. For guests with protected state, e.g. SEV-ES and SEV-SNP, KVM must assume the hypercall was made in 64-bit mode as the vCPU state needed to detect 64-bit mode is unavailable. Hacking the sev_smoke_test selftest to generate a KVM_HC_MAP_GPA_RANGE hypercall via VMGEXIT trips the WARN: ------------[ cut here ]------------ WARNING: CPU: 273 PID: 326626 at arch/x86/kvm/x86.h:180 complete_hypercall_exit+0x44/0xe0 [kvm] Modules linked in: kvm_amd kvm ... [last unloaded: kvm] CPU: 273 UID: 0 PID: 326626 Comm: sev_smoke_test Not tainted 6.12.0-smp--392e932fa0f3-feat #470 Hardware name: Google Astoria/astoria, BIOS 0.20240617.0-0 06/17/2024 RIP: 0010:complete_hypercall_exit+0x44/0xe0 [kvm] Call Trace: <TASK> kvm_arch_vcpu_ioctl_run+0x2400/0x2720 [kvm] kvm_vcpu_ioctl+0x54f/0x630 [kvm] __se_sys_ioctl+0x6b/0xc0 do_syscall_64+0x83/0x160 entry_SYSCALL_64_after_hwframe+0x76/0x7e </TASK> ---[ end trace 0000000000000000 ]---

Published: 2025-01-11 Last update: 2026-06-17 Assigner: 416baaa9-dc9f-4396-8d5f-8c081fb06d67 Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2024-55881 is rated Low Risk (25.7/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.20%). Monitor for updates and reassess as exploit intelligence or EPSS changes.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2024-55881

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 0.04% 0.20% +0.17%
2 2025-11-21 0.07% 0.04% -0.03%
3 2025-11-18 — 0.07% —

Full EPSS history (6 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2024-55881

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
5.5 3.1 MEDIUM
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H Click to expand
Attack vector (AV:L)
They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 1.8 3.6 [email protected]

Weakness enumeration for CVE-2024-55881

OS Trackers for CVE-2024-55881

vendor priority summary link
debian unimportant CVE-2024-55881 unimportant priority: Debian including 2 source packages (linux, linux-6.1), 6 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 6. https://security-tracker.debian.org/tracker/CVE-2024-55881
redhat low — https://access.redhat.com/security/cve/CVE-2024-55881
suse medium CVE-2024-55881 severity moderate: SUSE including 417 source package names (2.1.3-4.43:kernel-default-base-6.4.0-24.1.21.4, 2.1.3-6.5:kernel-default-6.4.0-25.1, …), 713 product×package rows across 128 product lines (Container suse/sl-micro/6.0/base-os-container, Container suse/sl-micro/6.0/kvm-os-container, … (128 product lines)): Fixed 362, Known Affected 231, Known Not Affected 120. https://www.suse.com/security/cve/CVE-2024-55881/
ubuntu medium CVE-2024-55881 medium priority: Ubuntu including 158 source packages (linux, linux-allwinner-5.19, …), 1551 status rows across 10 suites (bionic, focal, jammy, noble, oracular, plucky, questing, trusty, upstream, xenial): DNE 1145, released 168, ignored 147, not-affected 90, needed 1. https://ubuntu.com/security/CVE-2024-55881

Affected software / configurations for CVE-2024-55881

Vendor Product Version Raw CPE
linux linux_kernel >= 5.15.5, < 5.15.176 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
linux linux_kernel >= 5.16.1, < 6.1.122 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
linux linux_kernel >= 6.2, < 6.6.68 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
linux linux_kernel >= 6.7, < 6.12.7 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
linux linux_kernel 5.16 cpe:2.3:o:linux:linux_kernel:5.16:-:*:*:*:*:*:*
linux linux_kernel 5.16 cpe:2.3:o:linux:linux_kernel:5.16:rc2:*:*:*:*:*:*
linux linux_kernel 5.16 cpe:2.3:o:linux:linux_kernel:5.16:rc3:*:*:*:*:*:*
linux linux_kernel 5.16 cpe:2.3:o:linux:linux_kernel:5.16:rc4:*:*:*:*:*:*
linux linux_kernel 5.16 cpe:2.3:o:linux:linux_kernel:5.16:rc5:*:*:*:*:*:*
linux linux_kernel 5.16 cpe:2.3:o:linux:linux_kernel:5.16:rc6:*:*:*:*:*:*
linux linux_kernel 5.16 cpe:2.3:o:linux:linux_kernel:5.16:rc7:*:*:*:*:*:*
linux linux_kernel 5.16 cpe:2.3:o:linux:linux_kernel:5.16:rc8:*:*:*:*:*:*
linux linux_kernel 6.13 cpe:2.3:o:linux:linux_kernel:6.13:rc1:*:*:*:*:*:*
linux linux_kernel 6.13 cpe:2.3:o:linux:linux_kernel:6.13:rc2:*:*:*:*:*:*
linux linux_kernel 6.13 cpe:2.3:o:linux:linux_kernel:6.13:rc3:*:*:*:*:*:*

References for CVE-2024-55881

cvelogic Threat Intelligence