CVE-2026-90177 bpf: Check pointer type for all atomic RMW paths
A missing pointer type check in Linux kernel BPF atomic operations allows bypassing verification, potentially leading to privilege escalation or code execution.
- 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-2026-90177?
CVE-2026-90177 is a high-severity vulnerability in Linux, published on 17 Sep 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:
bpf: Check pointer type for all atomic RMW paths
Atomic RMW verification records an instruction pointer type only when the current destination is PTR_TO_ARENA. A second path can therefore reach the same instruction with an ordinary pointer without comparing it against the saved arena type.
The post-verification fixup uses the saved type to rewrite the instruction to BPF_PROBE_ATOMIC for every path. Record the actual destination type for all atomic RMW paths so the existing mismatch check rejects incompatible uses of one instruction.
Which versions are affected by CVE-2026-90177?
How do I fix CVE-2026-90177?
Apply the vendor's patch.
Is CVE-2026-90177 being exploited?
There is no known exploitation of CVE-2026-90177 in the wild and no public exploit code.
Sources
Also known as BELL-CVE-2026-90177, DEBIAN-CVE-2026-90177, GHSA-mgh7-vvq6-r2vr, UBUNTU-CVE-2026-90177.