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🐧 Linux
Not in CISA KEV

CVE-2026-72239

CVE-2026-72239 is a security vulnerability in Kernel. O3 Security confirms whether CVE-2026-72239 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.

x86/virt/sev: Revert "Drop WBINVD before setting MSR_AMD64_SYSCFG_SNP_EN"

Published
Aug 15, 2026
Updated
Aug 16, 2026
Affected
1 pkg
Patched
1 / 1
Exploits
None indexed
Exploitation data as of Aug 16, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Real-World Exposure

1 pkg affected
🐧Kernel

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects Linux packages — download data is not available via public APIs for these ecosystems.

Description

In the Linux kernel, the following vulnerability has been resolved:

x86/virt/sev: Revert "Drop WBINVD before setting MSR_AMD64_SYSCFG_SNP_EN"

Revert

99cf1fb58e68 ("x86/virt/sev: Drop WBINVD before setting MSR_AMD64_SYSCFG_SNP_EN").

Section 8.8 of the SNP spec says:

Before invoking SNP_INIT_EX with INIT_RMP set to 1, software must ensure that no CPUs contain dirty cache lines for the memory containing the RMP.

Cachelines can be moved from cache to cache in a dirty state. The wbinvd_on_all_cpus() before SNP_INIT_EX flushes the caches for each CPU, but if the IPIs for WBINVD race with this dirty cacheline movement, it is possible that they may not get flushed, violating the firmware requirement.

Doing wbinvd_on_all_cpus() before setting SNPEn is safer since the RMP table is not yet in use.

[ Heroically bisected by Srikanth. ] [ bp: Massage commit message. ]

Affected Packages

1 total 1 fixed
EcosystemPackageVulnerable rangeFix
🐧LinuxKernel7.1.0&&< 7.1.57.1.5

Detection & mitigation playbook

Open-source dependency
  1. Detect

    Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for Kernel. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.

  2. Fix

    Update Kernel to 7.1.5 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-72239 is resolved across your whole dependency graph.

  3. Workarounds

    If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

  4. How O3 protects you

    O3 pinpoints whether CVE-2026-72239 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Tailored to CVE-2026-72239. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

In the Linux kernel, the following vulnerability has been resolved: x86/virt/sev: Revert "Drop WBINVD before setting MSR_AMD64_SYSCFG_SNP_EN" Revert 99cf1fb58e68 ("x86/virt/sev: Drop WBINVD before setting MSR_AMD64_SYSCFG_SNP_EN"). Section 8.8 of the SNP spec says: Before invoking SNP_INIT_EX with INIT_RMP set to 1, software must ensure that no CPUs contain dirty cache lines for the memory containing the RMP. Cachelines can be moved from cache to cache in a dirty state. The wbinvd_on_all_cpus() before SNP_INIT_EX flushes the caches for each CPU, but if the IPIs for WBINVD race with
O3 Security · Impact-Aware SCA

Is CVE-2026-72239 in your dependencies?

O3 detects CVE-2026-72239 across Linux dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.