# 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.

- **Severity:** Not scored
- **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:** Yes
- **Published:** 17 Sep 2026
- **Updated:** 19 Oct 2026
- **Also known as:** BELL-CVE-2026-92515, DEBIAN-CVE-2026-92515, GHSA-wmq6-chwh-p7qg, UBUNTU-CVE-2026-92515

## 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.

## Is CVE-2026-92515 being exploited?

There is no known exploitation of CVE-2026-92515 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-92515 and fix it if it is affected.

What it is: 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.
Exploitation: There is no known exploitation of CVE-2026-92515 in the wild and no public exploit code.

Affected product: Linux. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-92515/ (Markdown: https://insights.sbomify.com/CVE-2026-92515/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-92515
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-92515
- OSV: https://osv.dev/vulnerability/CVE-2026-92515

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-92515/
Summaries are generated and may contain mistakes; the official description above is the record.