CVE-2026-43331

Kernel crash via KCOV GS-base invalidation

Published May 8, 2026 · Updated May 8, 2026

Denial of service in affected Linux Kernel releases allows local users to crash x86-64 systems by executing kexec with KCOV enabled. load_segments() changes segment registers and invalidates the GS base that KCOV uses for per-CPU data, so native_gdt_invalidate() enters an endless kernel-crash loop when instrumented code runs. The path requires CONFIG_KEXEC and CONFIG_KCOV on a 64-bit x86 kernel plus permission to load and execute a replacement kernel; 32-bit kernels are unaffected.

CVSS severity5.5
Medium
EPSS probability0.12%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Denial of service in affected Linux Kernel releases allows local users to crash x86-64 systems by executing kexec with KCOV enabled. load_segments() changes segment registers and invalidates the GS base that KCOV uses for per-CPU data, so native_gdt_invalidate() enters an endless kernel-crash loop when instrumented code runs. The path requires CONFIG_KEXEC and CONFIG_KCOV on a 64-bit x86 kernel plus permission to load and execute a replacement kernel; 32-bit kernels are unaffected.

The record

CVE
CVE-2026-43331
Published
May 8, 2026
Updated
May 8, 2026
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
T1499
Attack vector
local
Privileges
admin

Timeline

How it unfolded

  1. May 8, 2026CVE publishedPublication date reported by the CVE source.
  2. May 8, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0d345996e4cb573f8cc81d49b3ee9a7fd2035bef <1e3e98596c2769721ade0418434852fb3af4849a
  2. Affected versionversion=0d345996e4cb573f8cc81d49b3ee9a7fd2035bef <917e3ad3321e75ca0223d5ccf26ceda116aa51e1
  3. Affected versionversion=0d345996e4cb573f8cc81d49b3ee9a7fd2035bef <de05c66fab8847237a9ca216934e56d3ee837f08
  4. Affected versionversion=6.6

What conditions does exploitation require?

Attack vectorlocal
Required privilegesadmin

What is affected?

The Linux Kernel Organization · Linux Kernelversion=0d345996e4cb573f8cc81d49b3ee9a7fd2035bef <1e3e98596c2769721ade0418434852fb3af4849a; version=0d345996e4cb573f8cc81d49b3ee9a7fd2035bef <917e3ad3321e75ca0223d5ccf26ceda116aa51e1; version=0d345996e4cb573f8cc81d49b3ee9a7fd2035bef <de05c66fab8847237a9ca216934e56d3ee837f08; version=6.6

Published CVSS scores

5.5NIST NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesadmin
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

T1499Endpoint Denial of Service

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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