CVE-2026-43133: KVM: nSVM: Always use vmcb01 in VMLOAD/VMSAVE emulation
Vulnerability summary
CVE-2026-43133 is a high (CVSS 7.9) vulnerability in linux. EPSS estimates a 0.13% chance of exploitation in the next 30 days, higher than 2.8% of scored vulnerabilities.
Not severe (CVSS 7.9, local access); no exploitation reported by the 5 checked sources
Source freshness unavailable
How is this decided?Advisory lineage
Upstream 0 · Downstream 40 · Related 36Timeline
- 06-05-2026PublishedVulnerability first disclosed.
- 19-10-2026Last modifiedVulnerability information updated.
Description
In the Linux kernel, the following vulnerability has been resolved: KVM: nSVM: Always use vmcb01 in VMLOAD/VMSAVE emulation Commit cc3ed80ae69f ("KVM: nSVM: always use vmcb01 to for vmsave/vmload of guest state") made KVM always use vmcb01 for the fields controlled by VMSAVE/VMLOAD, but it missed updating the VMLOAD/VMSAVE emulation code to always use vmcb01. As a result, if VMSAVE/VMLOAD is executed by an L2 guest and is not intercepted by L1, KVM will mistakenly use vmcb02. Always use vmcb01 instead of the current VMCB.
CVSS metrics
5 scores · 4 sources · 2 versions- OSV · UbuntuEcosystem advisory · calculated7.9HighCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:H
- OSV · DebianEcosystem advisory · calculated7.9HighCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:H
- NVDNIST7.9HighCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:H
EPSS trend
Probability
0.13%
Chance of exploitation in the next 30 days
Percentile
3%
Versus all other CVEs
30-day change
No change 0.00 pp
From 0.13% on 04-10-2026
Known exploited
Compare KEV catalogs
CISA KEVNot in the CISA KEV catalog.
ENISA CNWNot in the ENISA CNW catalog.
CIRCLNot in the CIRCL catalog.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root cause- CWE-754Improper Check for Unusual or Exceptional ConditionsThe product does not check or incorrectly checks for unusual or exceptional conditions that are not expected to occur frequently during day to day operation of the product.
- CWE-628Function Call with Incorrectly Specified ArgumentsThe product calls a function, procedure, or routine with arguments that are not correctly specified.
Affected systems
Known conditions: local access, low-privilege account, no user interaction (CVSS vector). Other conditions: not stated in public data.
Ubuntu145 products
- linux< 5.15.0-186.196 | < 6.8.0-134.134 | All versions (No fix recorded)
- linux-allwinner-5.19All versions (No fix recorded)
- linux-aws< 5.15.0-1112.119 | < 6.8.0-1060.63 | All versions (No fix recorded)
- linux-aws-5.0All versions (No fix recorded)
- linux-aws-5.11All versions (No fix recorded)
Linux2 products
- linux≥ cc3ed80ae69f454c3d904af9f65394a540099723, < 10063e1251c1485034a018236080792ad083dcc5 | ≥ cc3ed80ae69f454c3d904af9f65394a540099723, < c3b7015000988ba35ecd5648f4b2283960f00543 | ≥ cc3ed80ae69f454c3d904af9f65394a540099723, < 3880e331b0b31d0d5d3702b124f6c93539cd478a | ≥ cc3ed80ae69f454c3d904af9f65394a540099723, < fce2fd4a2ca05670a91015aacccf96a1c26268fd | ≥ cc3ed80ae69f454c3d904af9f65394a540099723, < d464cf1ed900d47c85393d40b00017b6adfc2e6c | ≥ cc3ed80ae69f454c3d904af9f65394a540099723, < 0004ecb798b30e90d7ebfe74efae2d9423315a64 | ≥ cc3ed80ae69f454c3d904af9f65394a540099723, < 127ccae2c185f62e6ecb4bf24f9cb307e9b9c619 | 5.13
- linux_kernel≥ 5.13, < 5.15.202 | ≥ 5.16, < 6.1.165 | ≥ 6.2, < 6.6.128 | ≥ 6.7, < 6.12.75 | ≥ 6.13, < 6.18.16 | ≥ 6.19, < 6.19.6
Debian1 product
- linux< 6.1.170-1 | < 6.12.85-1 | < 6.19.6-1
3 vendors · 148 products
