CVE-2026-53282: x86/kexec: Push kjump return address even for non-kjump kexec

Severity: medium (CVSS 5.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-06-26 · updated 2026-07-08

Description

In the Linux kernel, the following vulnerability has been resolved: x86/kexec: Push kjump return address even for non-kjump kexec The version of purgatory code shipped by kexec-tools attempts to look above the top of its stack to find a return address for a kjump, even in a non-kjump kexec. After the commit in Fixes: the word above the stack might not be there, leading to a fault (which is at least now caught by my exception-handling code in kexec). That commit fixed things for the actual kjump path, but no longer "gratuitously" pushes the unused return address to the stack in the non-kjump path. Put that *back* in the non-kjump path, to prevent purgatory from crashing when trying to access it.

Affected products

Linux kernel: from 6.14 before 6.18.33; from 6.19 before 7.0.10; 7.1-rc1, 7.1-rc2, 7.1-rc3 — fixed in 6.18.33, 7.0.10

How to fix

Upgrade to a fixed version: Linux kernel 6.18.33, 7.0.10. Check the vendor advisory for mitigations.

References

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