CVE-2026-92515 bpf: Preserve unique-field state across nested structs
A local attacker can trigger a kernel warning and potential denial of service by crafting specific BTF data with duplicate fields in nested structs.
- 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-2026-92515?
CVE-2026-92515 is a denial of service 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: Preserve unique-field state across nested structs
btf_find_struct_field() initializes a fresh seen mask for every recursive descent. Unique special fields in different levels of the same aggregate therefore do not see one another. The duplicate fields can reach btf_parse_fields(), where they trigger an invariant WARN_ON_ONCE(). A crafted user BTF can consequently trigger the warning before map creation checks capabilities.
Initialize the seen mask once in btf_find_field() and pass the same pointer through struct, datasec, and nested-struct walks. This gives the entire field traversal one shared uniqueness state.
Which versions are affected by CVE-2026-92515?
How do I fix CVE-2026-92515?
Apply the vendor's patch.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2026-92515 being exploited?
There is no known exploitation of CVE-2026-92515 in the wild and no public exploit code.
Sources
Also known as BELL-CVE-2026-92515, DEBIAN-CVE-2026-92515, GHSA-wmq6-chwh-p7qg, UBUNTU-CVE-2026-92515.