# CVE-2026-64354: bpf: Validate BTF repeated field counts before expansion

> A local attacker can exploit an integer overflow in the Linux kernel BPF subsystem to trigger a buffer overflow, potentially leading to code execution or privilege escalation.

- **Severity:** High 7.8 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H`)
- **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:** 25 Jul 2026
- **Updated:** 19 Oct 2026
- **Also known as:** BELL-CVE-2026-64354, DEBIAN-CVE-2026-64354, GHSA-pwg2-g943-8mr4, ROOT-OS-UBUNTU-2204-CVE-2026-64354, UBUNTU-CVE-2026-64354

## What is CVE-2026-64354?

CVE-2026-64354 is a high-severity vulnerability in Linux kernel, published on 25 Jul 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: Validate BTF repeated field counts before expansion

btf_parse_struct_metas() walks user-supplied BTF during BPF_BTF_LOAD,
and btf_repeat_fields() expands repeatable fields from array elements
into the fixed BTF_FIELDS_MAX scratch array used by btf_parse_fields().

The remaining-capacity check performs the expanded field count calculation
in u32. A malformed BTF can wrap that calculation, causing the check to
pass even when the expanded field count exceeds the scratch array
capacity. The following memcpy() can then write past the end of the
array.

Use checked addition and multiplication before copying repeated fields
and reject impossible counts.

Weakness: CWE-190 (Integer Overflow or Wraparound)

## Which versions are affected by CVE-2026-64354?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2026-64354?

Apply the vendor's patch.

## Is CVE-2026-64354 being exploited?

There is no known exploitation of CVE-2026-64354 in the wild and no public exploit code.

## Other vulnerabilities in Linux kernel

- [CVE-2026-53266](https://insights.sbomify.com/CVE-2026-53266/): Linux Kernel Out-of-Bounds Write (high 8.8, exploited in the wild)
- [CVE-2013-6282](https://insights.sbomify.com/CVE-2013-6282/): Linux Kernel Improper Input Validation (high 8.8, exploited in the wild)
- [CVE-2022-0185](https://insights.sbomify.com/CVE-2022-0185/): Linux Kernel Heap-Based Buffer Overflow (high 8.4, exploited in the wild)
- [CVE-2013-2094](https://insights.sbomify.com/CVE-2013-2094/): Linux Kernel Privilege Escalation (high 8.4, exploited in the wild)
- [CVE-2026-53362](https://insights.sbomify.com/CVE-2026-53362/): Linux Kernel Unspecified (high 7.8, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-64354 and fix it if it is affected.

What it is: CVE-2026-64354 is a high-severity vulnerability in Linux kernel, published on 25 Jul 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-2026-64354 in the wild and no public exploit code.

Affected product: Linux kernel. 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-2026-64354/ (Markdown: https://insights.sbomify.com/CVE-2026-64354/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-64354
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-64354
- OSV: https://osv.dev/vulnerability/CVE-2026-64354

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-64354/
Summaries are generated and may contain mistakes; the official description above is the record.