# 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.

- **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:** 17 Sep 2026
- **Updated:** 21 Oct 2026
- **Also known as:** BELL-CVE-2026-90177, DEBIAN-CVE-2026-90177, GHSA-mgh7-vvq6-r2vr, UBUNTU-CVE-2026-90177

## 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.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-90177 and fix it if it is affected.

What it is: 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.
Exploitation: There is no known exploitation of CVE-2026-90177 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-2026-90177/ (Markdown: https://insights.sbomify.com/CVE-2026-90177/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-90177
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-90177
- OSV: https://osv.dev/vulnerability/CVE-2026-90177

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-90177/
Summaries are generated and may contain mistakes; the official description above is the record.