CVE-2023-54172 | x86/hyperv: Disable IBT when hypercall page lacks ENDBR instruction

In the Linux kernel, the following vulnerability has been resolved: x86/hyperv: Disable IBT when hypercall page lacks ENDBR instruction On hardware that supports Indirect Branch Tracking (IBT), Hyper-V VMs with ConfigVersion 9.3 or later support IBT in the guest. However, current versions of Hyper-V have a bug in that there's not an ENDBR64 instruction at the beginning of the hypercall page. Since hypercalls are made with an indirect call to the hypercall page, all hypercall attempts fail with an exception and Linux panics. A Hyper-V fix is in progress to add ENDBR64. But guard against the Linux panic by clearing X86_FEATURE_IBT if the hypercall page doesn't start with ENDBR. The VM will boot and run without IBT. If future Linux 32-bit kernels were to support IBT, additional hypercall page hackery would be needed to make IBT work for such kernels in a Hyper-V VM.

Published: 2025-12-30 Last update: 2026-06-17 Assigner: 416baaa9-dc9f-4396-8d5f-8c081fb06d67 Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67

Conclusion & alert: CVE-2023-54172 is rated Low Risk (6.3/100): low exploitation likelihood (EPSS 0.17%). Mandatory action: Low composite risk—no urgent action required; patch on your normal maintenance cycle and revisit priority if CVSS or EPSS increases.

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-2023-54172

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 0.02% 0.17% +0.15%
2 2025-12-31 0.02%

Full EPSS history (2 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2023-54172

CVSS metrics for this CVE.

No CVSS data in dataset for this CVE.

Weakness enumeration for CVE-2023-54172

OS Trackers for CVE-2023-54172

vendor priority summary link
debian unimportant CVE-2023-54172 unimportant priority: Debian including 1 source packages (linux), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2023-54172
redhat low https://access.redhat.com/security/cve/CVE-2023-54172
suse medium CVE-2023-54172 severity moderate: SUSE including 369 source package names (2.1.3-6.115:kernel-default-base-6.4.0-39.1.21.16, 2.1.3-7.146:kernel-rt-6.4.0-40.1, …), 831 product×package rows across 159 product lines (Container suse/sl-micro/6.0/base-os-container, Container suse/sl-micro/6.0/kvm-os-container, … (159 product lines)): Fixed 385, Known Affected 231, Known Not Affected 215. https://www.suse.com/security/cve/CVE-2023-54172/
ubuntu medium CVE-2023-54172 medium priority: Ubuntu including 157 source packages (linux, linux-allwinner-5.19, …), 1405 status rows across 9 suites (bionic, focal, jammy, noble, plucky, questing, trusty, upstream, xenial): DNE 1010, ignored 177, released 83, needed 75, not-affected 60. https://ubuntu.com/security/CVE-2023-54172

Affected software / configurations for CVE-2023-54172

Vendor Product Version Raw CPE
linux linux_kernel >= 5.18, < 6.1.45 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
linux linux_kernel >= 5.18, < 6.4.10 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
linux linux_kernel >= 5.18, < 6.5 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*

References for CVE-2023-54172

cvelogic Threat Intelligence