What’s Vulnerable › Vulnerabilities

CVE-2026-98937: perf/core: Check kernel access when kernel callchains are requested

• Severity: unknown
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.2% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-10-23 · updated 2026-10-26

Description

In the Linux kernel, the following vulnerability has been resolved: perf/core: Check kernel access when kernel callchains are requested perf_event_open() currently gates perf_allow_kernel() only on !attr.exclude_kernel. However, users can still request kernel callchain collection with attr.exclude_callchain_kernel == 0 even when attr.exclude_kernel == 1. That still requires kernel profiling privilege, but the existing check does not enforce it. Update the permission check to call perf_allow_kernel() when either kernel sampling is requested or kernel callchains are requested. This keeps permission checks aligned with requested data and prevents unprivileged use of kernel callchain capture.

Affected products

• Linux kernel: 2.6.31 — fixed in 7.3

How to fix

Upgrade to a fixed version: Linux kernel 7.3. Check the vendor advisory for mitigations.

References

• https://git.kernel.org/stable/c/132bee76097be421ab3012130b5b506324cf2be1
• https://git.kernel.org/stable/c/2581b43e162cfc43e6f5d8dd8d2b38f3441550de
• https://git.kernel.org/stable/c/6e187281f978a2bff98ead6aa40f8ddc9a2c9afb
• https://git.kernel.org/stable/c/a4573a3838ae4fc73b70019cfa1dac9aaea7cc2f

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