# CVE-2026-90300: bpf: Clear buf on error in __bpf_get_task_stack

> A local attacker with BPF privileges can read uninitialized kernel memory via stack trace helpers, potentially leaking sensitive data.

- **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:** 21 Oct 2026
- **Also known as:** AZL-102008, BELL-CVE-2026-90300, DEBIAN-CVE-2026-90300, GHSA-ghq7-v2f8-82jr, UBUNTU-CVE-2026-90300

## What is CVE-2026-90300?

CVE-2026-90300 is a 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: Clear buf on error in __bpf_get_task_stack

Both bpf_get_task_stack and bpf_get_task_stack_sleepable helpers that
use __bpf_get_task_stack have buf defined as ARG_PTR_TO_UNINIT_MEM
argument and we should initialize the buf on every return path.

Adding missing buf memset for __bpf_get_task_stack fail paths. This
provides deterministic buffer contents, which is useful when the buffer
is used directly as a map key.

## Which versions are affected by CVE-2026-90300?


## How do I fix CVE-2026-90300?

Apply the vendor's patch.

## Is CVE-2026-90300 being exploited?

There is no known exploitation of CVE-2026-90300 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-90300 and fix it if it is affected.

What it is: CVE-2026-90300 is a 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-2026-90300 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-2026-90300/ (Markdown: https://insights.sbomify.com/CVE-2026-90300/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-90300
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-90300
- OSV: https://osv.dev/vulnerability/CVE-2026-90300

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-90300/
Summaries are generated and may contain mistakes; the official description above is the record.