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CVE-2024-26816 Linux CVE debrief

CVE-2024-26816 is a Linux kernel hardening issue in x86 relocation handling for the .notes section. On kernels built with CONFIG_XEN_PV=y, symbols are emitted into .notes so Xen can find the startup_xen entry point. The flaw is that applying relocations there can expose KASLR-related address information through the world-readable /sys/kernel/notes interface. The fix is to skip relocations in .notes so the readable values match System.map and no longer reveal the base address information.

Vendor
Linux
Product
CVE-2024-26816
CVSS
MEDIUM 5.5
CISA KEV
Not listed in stored evidence
Original CVE published
2024-04-10
Original CVE updated
2026-05-12
Advisory published
2024-04-10
Advisory updated
2026-05-12

Who should care

Linux kernel maintainers, distro security teams, and operators of systems that use Xen PV-enabled kernels should care most. It is especially relevant where unprivileged local users can read /sys/kernel/notes and where kernel address randomization secrecy is important.

Technical summary

The CVE affects x86 kernel relocation processing for the .notes section. With CONFIG_XEN_PV=y, the kernel places text symbols in .notes for Xen boot-time discovery. Relocations applied to that section can leak KASLR base information because /sys/kernel/notes is readable by unprivileged users. The upstream fix ignores relocations in .notes, preserving the intended contents without exposing address offsets. NVD lists affected Linux kernel version ranges across multiple stable branches, and the record includes kernel stable patch references.

Defensive priority

Medium

Recommended defensive actions

  • Apply the Linux kernel updates that include the .notes relocation fix for your affected stable branch.
  • Prioritize patching Xen PV-enabled systems first, since the issue is tied to CONFIG_XEN_PV=y.
  • Review whether your environment exposes /sys/kernel/notes to unprivileged users and confirm the kernel package includes the fix.
  • Track vendor advisories and kernel stable patches linked in the official references for your distribution branch.
  • Use standard kernel hardening and update processes to reduce the risk of local address-information exposure.

Evidence notes

The CVE description states that when CONFIG_XEN_PV=y, symbols are emitted into .notes for Xen startup discovery and that relocations against .notes can expose the KASLR base because /sys/kernel/notes is world-readable. The described remediation is to skip relocations in .notes so the values match System.map. NVD marks the record as modified on 2026-05-12, but the CVE publication date remains 2024-04-10.

Official resources

Publicly disclosed through the CVE/NVD record on 2024-04-10. Later record modification dates do not change the original CVE publication date.