Bluetooth: L2CAP: Fix use-after-free in l2cap_unregister_user
Key facts
- Attack vector
- Adjacent network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Code execution
- 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. Impact type from CWE-416 and the CVSS impact.
Summary
In the Linux kernel, the following vulnerability has been resolved: Bluetooth: L2CAP: Fix use-after-free in l2cap_unregister_user After commit ab4eedb790ca ("Bluetooth: L2CAP: Fix corrupted list in hci_chan_del"), l2cap_conn_del() uses conn->lock to protect access to conn->users. However, l2cap_register_user() and l2cap_unregister_user() don't use conn->lock, creating a race condition where these functions can access conn->users and conn->hchan concurrently with l2cap_conn_del(). This can lead to use-after-free and list corruption bugs, as reported by syzbot. Fix this by changing l2cap_register_user() and l2cap_unregister_user() to use conn->lock instead of hci_dev_lock(), ensuring consistent locking for the l2cap_conn structure.
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
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| Linux | Linux | 6.6.84 to before 6.6.130; 6.12.20 to before 6.12.78; 6.13.8 to before 6.14 | 6.6.130, 6.12.78, 6.14 | Patch available | CNA |
| Linux | Linux | 6.14 and later | 6.6.130, 6.12.78, 6.18.20, 6.19.10, 7.0 | Patch available | CNA |
- Linux VendorLinux Affected 6.6.84 to before 6.6.130; 6.12.20 to before 6.12.78; 6.13.8 to before 6.14 Fixed in 6.6.130, 6.12.78, 6.14 Patch available CNA
- Linux VendorLinux Affected 6.14 and later Fixed in 6.6.130, 6.12.78, 6.18.20, 6.19.10, 7.0 Patch available CNA
CPE configurations NVD · 11
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | 6.6.84 to before 6.6.130; 6.12.20 to before 6.12.78; 6.13.8 to before 6.14; 6.14.1 to before 6.18.20; 6.19 to before 6.19.10 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:6.14:-:*:*:*:*:*:* | 6.14 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:6.14:rc3:*:*:*:*:*:* | 6.14 rc3 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:6.14:rc4:*:*:*:*:*:* | 6.14 rc4 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:6.14:rc5:*:*:*:*:*:* | 6.14 rc5 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:6.14:rc6:*:*:*:*:*:* | 6.14 rc6 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:6.14:rc7:*:*:*:*:*:* | 6.14 rc7 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:7.0:rc1:*:*:*:*:*:* | 7.0 rc1 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:7.0:rc2:*:*:*:*:*:* | 7.0 rc2 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:7.0:rc3:*:*:*:*:*:* | 7.0 rc3 | Vulnerable | Linux |
- cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* Versions 6.6.84 to before 6.6.130; 6.12.20 to before 6.12.78; 6.13.8 to before 6.14; 6.14.1 to before 6.18.20; 6.19 to before 6.19.10 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:6.14:-:*:*:*:*:*:* Versions 6.14 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:6.14:rc3:*:*:*:*:*:* Versions 6.14 rc3 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:6.14:rc4:*:*:*:*:*:* Versions 6.14 rc4 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:6.14:rc5:*:*:*:*:*:* Versions 6.14 rc5 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:6.14:rc6:*:*:*:*:*:* Versions 6.14 rc6 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:6.14:rc7:*:*:*:*:*:* Versions 6.14 rc7 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:7.0:rc1:*:*:*:*:*:* Versions 7.0 rc1 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:7.0:rc2:*:*:*:*:*:* Versions 7.0 rc2 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:7.0:rc3:*:*:*:*:*:* Versions 7.0 rc3 Vulnerable ·Linux
Remediation
- Fix · CNA Linux (Linux) Fixed in 6.6.130, 6.12.78, 6.14
- Fix · CNA Linux (Linux) Fixed in 6.6.130, 6.12.78, 6.18.20, 6.19.10, 7.0
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: Fix deferred |
| Red Hat Enterprise Linux 9 | Affected | No fix yet: Fix deferred |
Not affected: 4 products
- Red Hat Enterprise Linux 6
- Red Hat Enterprise Linux 7
- Red Hat Enterprise Linux 8
- Red Hat Enterprise Linux 9
Timeline
- 2026-10-02 Threatist record created from CVE-2026-23461
- 2026-10-03 Alias added: GHSA-ggw5-jw3c-r95v
- 2026-10-16 CISA SSVC decision points changed
- 2026-10-16 Priority changed: LOW → MEDIUM
- 2026-10-19 Weakness changed · CISA ADP
- 2026-10-21 Priority changed: MEDIUM → LOW
- 2026-10-29 Affected versions changed · Red Hat
- 2026-11-01 Priority changed: LOW → MEDIUM
References
Patch 5
- https://git.kernel.org/stable/c/11a87dd5df428a4b79a84d2790cac7f3c73f1f0d
- https://git.kernel.org/stable/c/c22a5e659959eb77c2fbb58a5adfaf3c3dab7abf
- https://git.kernel.org/stable/c/da3000cbe4851458a22be38bb18c0689c39fdd5f
- https://git.kernel.org/stable/c/71030f3b3015a412133a805ff47970cdcf30c2b8
- https://git.kernel.org/stable/c/752a6c9596dd25efd6978a73ff21f3b592668f4a
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Sources
- CVE-2026-23461 · CVE Program
- CVE-2026-23461 · NVD
- FIRST EPSS
- GHSA-ggw5-jw3c-r95v · GitHub Advisory Database · CC BY 4.0
- CVE-2026-23461 · Red Hat security data · CC BY 4.0
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