CVE-2023-53756: linux

CVSS: UnknownDeferred
AliasesUBUNTU-CVE-2023-53756DEBIAN-CVE-2023-53756
Published 08-12-2025Last modified 11-05-2026
Open JSON

Vulnerability summary

CVE-2023-53756 is a vulnerability in linux with no CVSS score yet. EPSS estimates a 0.19% chance of exploitation in the next 30 days, higher than 8.2% of scored vulnerabilities.

Overall risk
0/100
0100
Minimal · default modelHow is this calculated?
CVSS score
Not scored
010
No CVSS score recorded
EPSS score
0.19%
0%100%
Low · 0.00 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Advisory lineage

Upstream 0 · Downstream 2
RHSA-2023:3465RHSA-2023:6583

Timeline

  1. 08-12-2025
    PublishedVulnerability first disclosed.
  2. 11-05-2026
    Last modifiedVulnerability information updated.

Description

In the Linux kernel, the following vulnerability has been resolved: KVM: VMX: Fix crash due to uninitialized current_vmcs KVM enables 'Enlightened VMCS' and 'Enlightened MSR Bitmap' when running as a nested hypervisor on top of Hyper-V. When MSR bitmap is updated, evmcs_touch_msr_bitmap function uses current_vmcs per-cpu variable to mark that the msr bitmap was changed. vmx_vcpu_create() modifies the msr bitmap via vmx_disable_intercept_for_msr -> vmx_msr_bitmap_l01_changed which in the end calls this function. The function checks for current_vmcs if it is null but the check is insufficient because current_vmcs is not initialized. Because of this, the code might incorrectly write to the structure pointed by current_vmcs value left by another task. Preemption is not disabled, the current task can be preempted and moved to another CPU while current_vmcs is accessed multiple times from evmcs_touch_msr_bitmap() which leads to crash. The manipulation of MSR bitmaps by callers happens only for vmcs01 so the solution is to use vmx->vmcs01.vmcs instead of current_vmcs. BUG: kernel NULL pointer dereference, address: 0000000000000338 PGD 4e1775067 P4D 0 Oops: 0002 [#1] PREEMPT SMP NOPTI ... RIP: 0010:vmx_msr_bitmap_l01_changed+0x39/0x50 [kvm_intel] ... Call Trace: vmx_disable_intercept_for_msr+0x36/0x260 [kvm_intel] vmx_vcpu_create+0xe6/0x540 [kvm_intel] kvm_arch_vcpu_create+0x1d1/0x2e0 [kvm] kvm_vm_ioctl_create_vcpu+0x178/0x430 [kvm] kvm_vm_ioctl+0x53f/0x790 [kvm] __x64_sys_ioctl+0x8a/0xc0 do_syscall_64+0x5c/0x90 entry_SYSCALL_64_after_hwframe+0x63/0xcd

CVSS metrics

Risk metrics not yet published.

EPSS trend

Probability

0.19%

Chance of exploitation in the next 30 days

Percentile

8%

Versus all other CVEs

30-day change

0.00 pp

From 0.19% on 20-09-2026

20-09-202620-10-2026
EPSS score
0.19%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

No weakness data has been published for this record.

Affected systems

Ubuntu120 products
  • linuxAll versions (No fix recorded) | < 5.15.0-79.86
  • linux-allwinner-5.19All versions (No fix recorded)
  • linux-awsAll versions (No fix recorded) | < 5.15.0-1042.47
  • linux-aws-5.0All versions (No fix recorded)
  • linux-aws-5.11All versions (No fix recorded)
Debian1 product
  • linux< 6.1.20-1
Linux1 product
  • linux≥ ceef7d10dfb6284d512c499292e6daa35ea83f90, < 6baebcecf09acd19e2bab1c2911dcdba5d48a1dc | ≥ ceef7d10dfb6284d512c499292e6daa35ea83f90, < 6e7bc50f97c9855da83f1478f722590defd45ff2 | ≥ ceef7d10dfb6284d512c499292e6daa35ea83f90, < b2de2b4d4e007f9add46ea8dc06f781835e3ea9f | ≥ ceef7d10dfb6284d512c499292e6daa35ea83f90, < 3ba95cc671c025d0d2a1c7d5e2930f0ff0980cf4 | ≥ ceef7d10dfb6284d512c499292e6daa35ea83f90, < 93827a0a36396f2fd6368a54a020f420c8916e9b | 4.18

3 vendors · 122 products

References

9 links