5.5

CVE-2026-45987: KVM: nSVM: Sync interrupt shadow to cached vmcb12 after VMRUN of L2

Analyzed
AliasesUBUNTU-CVE-2026-45987DEBIAN-CVE-2026-45987
Published 27-05-2026Last modified 14-06-2026

Vulnerability summary

CVE-2026-45987 is a medium (CVSS 5.5) vulnerability in linux. EPSS estimates a 0.12% chance of exploitation in the next 30 days, higher than 2% of scored vulnerabilities.

Priority
Routine

Not severe (CVSS 5.5, local access); no exploitation reported by the 5 checked sources

Source freshness unavailable

How is this decided?
CVSS score
5.5/10
010
Medium · v3.1 (NVD)
EPSS score
0.12%
0%100%
Low · -0.04 pp in 30 days
KEVNot listedNot listed by any tracked catalog.
RansomwareNot flaggedNo ransomware use recorded.
Public exploits0No public exploits recorded

Advisory lineage

Upstream 0 · Downstream 46 · Related 46
OPENSUSE-SU-2026:10954-1OPENSUSE-SU-2026:21555-1SUSE-SU-2026:22809-1SUSE-SU-2026:22810-1SUSE-SU-2026:22903-1SUSE-SU-2026:22904-1

Timeline

  1. 27-05-2026
    PublishedVulnerability first disclosed.
  2. 14-06-2026
    Last modifiedVulnerability information updated.

Description

In the Linux kernel, the following vulnerability has been resolved: KVM: nSVM: Sync interrupt shadow to cached vmcb12 after VMRUN of L2 After VMRUN in guest mode, nested_sync_control_from_vmcb02() syncs fields written by the CPU from vmcb02 to the cached vmcb12. This is because the cached vmcb12 is used as the authoritative copy of some of the controls, and is the payload when saving/restoring nested state. int_state is also written by the CPU, specifically bit 0 (i.e. SVM_INTERRUPT_SHADOW_MASK) for nested VMs, but it is not sync'd to cached vmcb12. This does not cause a problem if KVM_SET_NESTED_STATE preceeds KVM_SET_VCPU_EVENTS in the restore path, as an interrupt shadow would be correctly restored to vmcb02 (KVM_SET_VCPU_EVENTS overwrites what KVM_SET_NESTED_STATE restored in int_state). However, if KVM_SET_VCPU_EVENTS preceeds KVM_SET_NESTED_STATE, an interrupt shadow would be restored into vmcb01 instead of vmcb02. This would mostly be benign for L1 (delays an interrupt), but not for L2. For L2, the vCPU could hang (e.g. if a wakeup interrupt is delivered before a HLT that should have been in an interrupt shadow). Sync int_state to the cached vmcb12 in nested_sync_control_from_vmcb02() to avoid this problem. With that, KVM_SET_NESTED_STATE restores the correct interrupt shadow state, and if KVM_SET_VCPU_EVENTS follows it would overwrite it with the same value.

CVSS metrics

3 scores · 3 sources · 1 version

EPSS trend

Probability

0.12%

Chance of exploitation in the next 30 days

Percentile

2%

Versus all other CVEs

30-day change

Decrease -0.04 pp

From 0.16% on 04-10-2026

04-10-202603-11-2026

Known exploited

Compare KEV catalogs
CISA KEV

Not in the CISA KEV catalog.

ENISA CNW

Not in the ENISA CNW catalog.

CIRCL

Not in the CIRCL catalog.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

No weakness data has been published for this record.

Affected systems

Version check

Known conditions: local access, low-privilege account, no user interaction (CVSS vector). Other conditions: not stated in public data.

Ubuntu147 products
  • linux< 5.15.0-186.196 | < 6.8.0-136.136 | All versions (No fix recorded) | < 7.0.0-27.27
  • linux-allwinner-5.19All versions (No fix recorded)
  • linux-aws< 5.15.0-1112.119 | < 6.8.0-1061.64 | All versions (No fix recorded) | < 7.0.0-1008.8
  • linux-aws-5.0All versions (No fix recorded)
  • linux-aws-5.11All versions (No fix recorded)
Linux2 products
  • linux≥ cc440cdad5b7a4c1de12dace725209eb3e0cf663, < 0c1f74d8b74d8a31751fb6ea5417e48e02c93b58 | ≥ cc440cdad5b7a4c1de12dace725209eb3e0cf663, < 4b44aa1a134e499c4517597118378b308602a16c | ≥ cc440cdad5b7a4c1de12dace725209eb3e0cf663, < e39a77a9b1e17d2d831c304eafac4c41a784a0be | ≥ cc440cdad5b7a4c1de12dace725209eb3e0cf663, < 1709418535a8df95532999d61b03d59975280258 | ≥ cc440cdad5b7a4c1de12dace725209eb3e0cf663, < 2f950eeb27af6885416232761700b8820cae0a61 | ≥ cc440cdad5b7a4c1de12dace725209eb3e0cf663, < 497f6af9679fc9c6ce2f438e11ed5d51b1aa8297 | ≥ cc440cdad5b7a4c1de12dace725209eb3e0cf663, < e0377e52f3c10ee572732d11b04625b7f517a862 | ≥ cc440cdad5b7a4c1de12dace725209eb3e0cf663, < 03bee264f8ebfd39e0254c98e112d033a7aa9055 | 5.8
  • linux_kernel≥ 5.8, < 5.10.258 | ≥ 5.11, < 5.15.209 | ≥ 5.16, < 6.1.175 | ≥ 6.2, < 6.6.140 | ≥ 6.7, < 6.12.86 | ≥ 6.13, < 6.18.27 | ≥ 6.19, < 7.0.4
Debian1 product
  • linux< 6.1.176-1 | < 6.12.86-1 | < 7.0.4-1

3 vendors · 150 products

References

46 links
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