CVE-2026-31528 perf: Make sure to use pmu_ctx->pmu for groups
A memory corruption vulnerability in the Linux kernel perf subsystem allows out-of-bounds access, potentially leading to code execution or privilege escalation.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-31528?
CVE-2026-31528 is a high-severity memory corruption vulnerability in Linux kernel, published on 22 Apr 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
In the Linux kernel, the following vulnerability has been resolved:
perf: Make sure to use pmu_ctx->pmu for groups
Oliver reported that x86_pmu_del() ended up doing an out-of-bound memory access when group_sched_in() fails and needs to roll back.
This *should* be handled by the transaction callbacks, but he found that when the group leader is a software event, the transaction handlers of the wrong PMU are used. Despite the move_group case in perf_event_open() and group_sched_in() using pmu_ctx->pmu.
Turns out, inherit uses event->pmu to clone the events, effectively undoing the move_group case for all inherited contexts. Fix this by also making inherit use pmu_ctx->pmu, ensuring all inherited counters end up in the same pmu context.
Similarly, __perf_event_read() should use equally use pmu_ctx->pmu for the group case.
Which versions are affected by CVE-2026-31528?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2026-31528?
Apply the vendor's patch.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2026-31528 being exploited?
There is no known exploitation of CVE-2026-31528 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as AZL-83345, BELL-CVE-2026-31528, DEBIAN-CVE-2026-31528, GHSA-37p2-prpf-4qx7, ROOT-OS-DEBIAN-13-CVE-2026-31528, ROOT-OS-UBUNTU-2404-CVE-2026-31528 and 1 more.