CVE-2026-64555: linux
Vulnerability summary
CVE-2026-64555 is a high (CVSS 8.8) vulnerability in linux. EPSS estimates a 0.13% chance of exploitation in the next 30 days, higher than 2.2% of scored vulnerabilities.
Advisory lineage
Upstream 0 · Downstream 17 · Related 13Timeline
- 27-07-2026PublishedVulnerability first disclosed.
- 17-08-2026Last modifiedVulnerability information updated.
Description
In the Linux kernel, the following vulnerability has been resolved: KVM: arm64: nv: Fix SPSR_EL2 restore in kvm_hyp_handle_mops() kvm_hyp_handle_mops() resets the single-step state machine as part of rewinding state for a MOPS exception by modifying vcpu_cpsr() and writing the result directly into hardware. In the case of nested virtualization, vcpu_cpsr() is a synthetic value such that the rest of KVM can deal with vEL2 cleanly. That means the value requires translation before being written into hardware, which is unfortunately missing from the MOPS handler. Fix it by directly modifying SPSR_EL2 and avoiding the synthetic state altogether, which will be resynchronized on the next 'full' exit back to KVM.
CVSS metrics
4 scores · 4 sources · 1 version- OSV · UbuntuEcosystem advisory · calculated8.8HighCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
- OSV · DebianEcosystem advisory · calculated8.8HighCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
- NVDNIST8.8HighCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
EPSS trend
Probability
0.13%
Chance of exploitation in the next 30 days
Percentile
2%
Versus all other CVEs
30-day change
0.00 pp
From 0.13% on 19-09-2026
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeNo weakness data has been published for this record.
Affected systems
Ubuntu142 products
- linuxAll versions (No fix recorded) | < 6.8.0-147.147 | < 7.0.0-38.38
- linux-allwinner-5.19All versions (No fix recorded)
- linux-awsAll versions (No fix recorded) | < 6.8.0-1067.70 | < 7.0.0-1014.14
- linux-aws-5.0All versions (No fix recorded)
- linux-aws-5.11All versions (No fix recorded)
Debian2 products
- linux< 6.12.100-1 | < 7.1.5-1
- linux-6.12< 6.12.100-1~deb12u1
Linux1 product
- linux≥ 2de451a329cf662beeba71f63c7f83ee24ca6642, < 10a568010e827108d149779908850afaec898846 | ≥ 2de451a329cf662beeba71f63c7f83ee24ca6642, < 884b44256041ec6b2dcbe8e6a67384d26145cba1 | ≥ 2de451a329cf662beeba71f63c7f83ee24ca6642, < dd3b237eb7780d65eae296d3d3a70012b6e7a02f | ≥ 2de451a329cf662beeba71f63c7f83ee24ca6642, < ff1022c3de46753eb7eba2f6efd990569e66ff95 | 6.7
3 vendors · 145 products
