CVE-2026-43240
MediumIn the Linux kernel, the following vulnerability has been resolved: x86/kexec: add a sanity check on previous kernel's ima kexec buffer When the second-stage kernel is booted via kexec with a limiting command line such as "mem=<size>", the physical range that contains the carried over IMA measurement list may fall outside the truncated RAM leading to a kernel panic. BUG: unable to handle page fault for address: ffff97793ff47000 RIP: ima_restore_measurement_list+0xdc/0x45a #PF: error_code(0x0000) – not-present page Other architectures already validate the range with page_is_ram(), as done in commit cbf9c4b9617b ("of: check previous kernel's ima-kexec-buffer against memory bounds") do a similar check on x86. Without carrying the measurement list across kexec, the attestation would fail.
CVSS 3.1 score
5.5
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Affected versions
Linux kernel versions
6.0
and later are affected. Fixed in
6.1.165,
6.6.128,
6.12.75,
6.18.16,
6.19.6,
7.0
and their respective stable series.
References
The following references provide additional information about CVE-2026-43240 including vendor advisories, patch commits, exploit details, and third-party analysis. Links are sourced from the NIST NVD database.
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PatchKernel patch commithttps://git.kernel.org/stable/c/22e460b6333a5f818b042ac89201f8e735556f4a
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PatchKernel patch commithttps://git.kernel.org/stable/c/37f18915a261afe84dab462624ed829cddb77a9b
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PatchKernel patch commithttps://git.kernel.org/stable/c/4d7a8f5f28187e3d2958b2a134473da2665207e7
Frequently asked questions
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What is CVE-2026-43240?
CVE-2026-43240 is a Medium severity Linux kernel vulnerability with a CVSS score of 5.5 out of 10 . It affects Linux kernel versions from 6.0 onward and has been patched in 6.1.165, 6.6.128, 6.12.75 and others. CVE-2026-43240 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
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What is the CVSS score for CVE-2026-43240?
CVE-2026-43240 has a CVSS score of 5.5 out of 10, rated Medium severity (CVSS 3.1). The vector string is
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H. -
Is there a patch available for CVE-2026-43240?
Yes — CVE-2026-43240 has been patched. Fixed versions include 6.1.165, 6.6.128, 6.12.75 and others. If you are running Linux kernel 6.0 or later up to the fix versions, apply the relevant patch for your kernel branch.
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Is CVE-2026-43240 actively exploited?
No — CVE-2026-43240 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.