# CVE-2026-98816: bpf: Fix overflow of jump offset in constant blinding

> A local attacker with BPF privileges can trigger a kernel crash via integer overflow in BPF constant blinding when hardening is enabled.

- **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:** 18 Oct 2026
- **Updated:** 19 Oct 2026
- **Also known as:** AZL-109149, BELL-CVE-2026-98816, DEBIAN-CVE-2026-98816, GHSA-6x96-v5fq-fjjw, UBUNTU-CVE-2026-98816

## What is CVE-2026-98816?

CVE-2026-98816 is a vulnerability in Linux, published on 18 Oct 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: Fix overflow of jump offset in constant blinding

bpf_jit_blind_insn() rewrites 'if rX op imm goto off' into:

  AX = imm ^ rnd
  AX ^= rnd
  if rX op AX goto off

and subtracts 2 from off when the jump is backward. off is s16, so
-32767 and -32768 wrap and the jump goes 32767 insns forward, past the
end of the prog. The jump is inside the patch, hence bpf_adj_branches()
doesn't check it. The kernel crashes when such prog runs with
bpf_jit_harden=2.

Return -ERANGE in such case. bpf_jit_blind_constants() fails the same
way when blinding of other insns moves a jump out of range.

## Which versions are affected by CVE-2026-98816?


## How do I fix CVE-2026-98816?

Apply the vendor's patch.

## Is CVE-2026-98816 being exploited?

There is no known exploitation of CVE-2026-98816 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-98816 and fix it if it is affected.

What it is: CVE-2026-98816 is a vulnerability in Linux, published on 18 Oct 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-2026-98816 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-2026-98816/ (Markdown: https://insights.sbomify.com/CVE-2026-98816/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-98816
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-98816
- OSV: https://osv.dev/vulnerability/CVE-2026-98816

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-98816/
Summaries are generated and may contain mistakes; the official description above is the record.