Bluetooth: ISO: hold sk properly in iso_conn_ready
Key facts
- Attack vector
- Adjacent network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- —
- Confidentiality · integrity · availability
- High · High · High
- Fix status
- Partial Red Hat: 2 without a fix
Attack profile from CVSS 3.1 · CNA. Fix status from CNA and Red Hat.
Summary
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.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Total
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
Remediation
- Fix · CNA Linux (Linux) Fixed in 6.1.191, 6.6.160, 6.12.114, 6.18.44, 7.1.8, 7.2
Vendor assessments
Red Hat
Red Hat rating: Moderate. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux 10 | Affected | No fix yet |
| Red Hat Enterprise Linux 9 | Affected | No fix yet |
Not affected: 3 products
- Red Hat Enterprise Linux 6
- Red Hat Enterprise Linux 7
- Red Hat Enterprise Linux 8
Timeline
- 2026-10-02 Threatist record created from CVE-2026-74537
- 2026-10-03 Alias added: GHSA-4f56-g5vg-w2cg
- 2026-10-18 CISA SSVC decision points changed
- 2026-10-18 Priority changed: LOW → MEDIUM
- 2026-10-21 Fix available: Linux/Linux@44590dc53c9e949d2fed399a571a89c3d7d0b245, Linux/[email protected], Linux/[email protected] +1 · CNA
- 2026-10-21 2 new references · CNA
- 2026-10-26 Affected versions changed · Red Hat
- 2026-10-26 CVSS score changed · Red Hat
- 2026-10-30 Affected versions changed · Red Hat
- 2026-10-30 Fix available: Linux/[email protected], Linux/Linux@622180fe44fb52d4d7bafcd67922959823fec263 · CNA
- 2026-10-30 1 new reference · CNA
References
Other 6
- 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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Sources
- CVE-2026-74537 · CVE Program
- CVE-2026-74537 · NVD
- FIRST EPSS
- GHSA-4f56-g5vg-w2cg · GitHub Advisory Database · CC BY 4.0
- CVE-2026-74537 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences