# CVE-2026-64508: bpf: Support for hardening against JIT spraying

> Attackers can exploit JIT memory reuse to bypass branch predictor hardening, potentially leading to privilege escalation or code execution in the Linux kernel.

- **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:** 25 Jul 2026
- **Updated:** 19 Aug 2026
- **Also known as:** AZL-93857, BELL-CVE-2026-64508, DEBIAN-CVE-2026-64508, GHSA-667g-8hv2-vmxj, ROOT-OS-UBUNTU-2204-CVE-2026-64508, UBUNTU-CVE-2026-64508

## What is CVE-2026-64508?

CVE-2026-64508 is a vulnerability in Linux, 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: Support for hardening against JIT spraying

The BPF JIT allocator packs many small programs into larger executable
allocations and reuses space within those allocations as programs are
loaded and freed. When fresh code is written into space that a previous
program occupied, an indirect jump into the new program can reuse a branch
prediction left behind by the old one.

Flush the indirect branch predictors before reusing JIT memory so that
indirect jumps into a newly written program don't reuse predictions from an
old program that occupied the same space.

Introduce bpf_arch_pred_flush_enabled static key and bpf_arch_pred_flush
static call for flushing the branch predictors on JIT memory reuse.
Architectures that need a flush, can update it to a predictor flush
function. By default, its a NOP and does not emit any CALL.

Allocations larger than a pack are not covered by this flush. That is safe
because cBPF programs (the unprivileged attack surface) are bounded well
below a pack size. Issue a warning if this assumption is ever violated
while the flush is active.

## Which versions are affected by CVE-2026-64508?


## How do I fix CVE-2026-64508?

Apply the vendor's patch.

## Is CVE-2026-64508 being exploited?

There is no known exploitation of CVE-2026-64508 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-64508 and fix it if it is affected.

What it is: CVE-2026-64508 is a vulnerability in Linux, 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-2026-64508 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-2026-64508/ (Markdown: https://insights.sbomify.com/CVE-2026-64508/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-64508
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-64508
- OSV: https://osv.dev/vulnerability/CVE-2026-64508

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-64508/
Summaries are generated and may contain mistakes; the official description above is the record.