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no cvss —

CVE-2026-93266 json

arm64: RSI: fix field-spanning write warning in attestation token init

published 2026-09-24 45 d ago modified 2026-10-19 21 d ago also EUVD-2026-86138

cvss
—
not scored
cisa kev
Not listed
not in CISA's catalog
epss
0.2%
EPSS 0.2% chance of exploitation in 30 days, percentile 8%
public exploits
0
none known

Summary

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

arm64: RSI: fix field-spanning write warning in attestation token init

The challenge is passed in registers a1 through a8. However, copying to &regs.a1 makes FORTIFY treat the destination as the single a1 field, resulting in a field-spanning write warning. [1]

Overlay the SMCCC register structure with an RSI-specific argument layout and copy the challenge into an explicit 64-byte array. This keeps the existing a1-a8 argument encoding while giving the copy a correctly sized destination object.

[1] memcpy: detected field-spanning write (size 64) of single field "&regs.a1" at ./arch/arm64/include/asm/rsi_cmds.h:119 (size 8) WARNING: ./arch/arm64/include/asm/rsi_cmds.h:119 at rsi_attestation_token_init+0xdc/0xf8 [arm_cca_guest], CPU#0: cat/3314

Patch / fix

  • Linux Linux 6.18.52, 7.2.6, 7.3
  • linux Debian 14 7.2.6-1

debian advisories DEBIAN-CVE-2026-93266

  • linux Ubuntu 26.04 LTS 7.0.0-42.42
  • linux-aws Ubuntu 26.04 LTS 7.0.0-1016.17
  • linux-gcp Ubuntu 26.04 LTS 7.0.0-1016.18
  • linux-ibm Ubuntu 26.04 LTS 7.0.0-1017.17
  • linux-riscv Ubuntu 26.04 LTS 7.0.0-42.42.1
  • linux-oracle Ubuntu 26.04 LTS 7.0.0-1015.16
  • linux-hwe-7.0 Ubuntu 24.04 LTS 7.0.0-42.42~24.04.1
  • linux-oem-7.0 Ubuntu 26.04 LTS 7.0.0-1017.17

ubuntu advisories UBUNTU-CVE-2026-93266

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • kernel-source openSUSE Tumbleweed 7.2.9-1.1

opensuse advisories openSUSE-SU-2026:12074-1

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-93266 updated cvss 5.5

kernel: arm64: RSI: fix field-spanning write warning in attestation token init

  • Red Hat Enterprise Linux 6 perf, kernel, python-perf, kernel-kdump, kernel-firmware, kernel-bootwrapper, +1 more Red Hat Enterprise Linux 7 perf, kernel, bpftool, kernel-rt, python-perf, kernel-kdump, +8 more Red Hat Enterprise Linux 8 perf, kernel, bpftool, kernel-rt, kernel-core, kernel-tools, +29 more Red Hat Enterprise Linux 9 rv, perf, rtla, kernel, bpftool, libperf, +83 more Red Hat Enterprise Linux 10 kernel Red Hat OpenShift Container Platform 4 openshift/ose-rhel-coreos-8, openshift/ose-rhel-coreos-9
    +1 more products
    Red Hat OpenShift Container Platform 5 openshift/ose-rhel-coreos-9
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

Exploit prediction

0.18% chance of exploitation in the next 30 days, higher than 8% of all scored CVEs (FIRST EPSS, 2026-11-08).

Affected products

  • Linux Linux

Classification

Technology feeds

References

Sources

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