CVE-2026-23461
Bluetooth: L2CAP: Fix use-after-free in l2cap_unregister_user
HIGH 8.8
At a glance
- Source
- NVD
- EPSS
- EPSS 0.23 % · percentile 14 ()
- State
- PUBLISHED
- Published
- Updated
- Assigner
- Linux
- NVD status
- Modified
Description
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.
Weaknesses (CWE)
References
- 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
Scores
| Version | Score | Vector | Scored by |
|---|---|---|---|
| CVSS 3.1 | HIGH 8.8 | CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H | Linux |
| CVSS 3.1 | HIGH 8.8 | CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H | NVD · 416baaa9-dc9f-4396-8d5f-8c081fb06d67 (Secondary) |
European references
- ENISA EUVD · EUVD-2026-18722
- GCVE · GCVE-0-2026-23461
CERT-FR advisories
- CERTFR-2026-AVI-1066 — Multiples vulnérabilités dans le noyau Linux d'Ubuntu · cert.ssi.gouv.fr
- CERTFR-2026-AVI-0954 — Multiples vulnérabilités dans le noyau Linux d'Ubuntu · cert.ssi.gouv.fr
- CERTFR-2026-AVI-0926 — Multiples vulnérabilités dans le noyau Linux d'Ubuntu · cert.ssi.gouv.fr
- CERTFR-2026-AVI-0697 — Multiples vulnérabilités dans le noyau Linux de SUSE · cert.ssi.gouv.fr
- CERTFR-2026-AVI-0664 — Multiples vulnérabilités dans le noyau Linux de SUSE · cert.ssi.gouv.fr
- CERTFR-2026-AVI-0548 — Multiples vulnérabilités dans le noyau Linux de Debian · cert.ssi.gouv.fr
Affected configurations (NVD CPE)
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*≥ 6.6.84 < 6.6.130cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*≥ 6.12.20 < 6.12.78cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*≥ 6.13.8 < 6.14cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*≥ 6.14.1 < 6.18.20cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*≥ 6.19 < 6.19.10cpe:2.3:o:linux:linux_kernel:6.14:-:*:*:*:*:*:*cpe:2.3:o:linux:linux_kernel:6.14:rc3:*:*:*:*:*:*cpe:2.3:o:linux:linux_kernel:6.14:rc4:*:*:*:*:*:*cpe:2.3:o:linux:linux_kernel:6.14:rc5:*:*:*:*:*:*cpe:2.3:o:linux:linux_kernel:6.14:rc6:*:*:*:*:*:*cpe:2.3:o:linux:linux_kernel:6.14:rc7:*:*:*:*:*:*cpe:2.3:o:linux:linux_kernel:7.0:rc1:*:*:*:*:*:*cpe:2.3:o:linux:linux_kernel:7.0:rc2:*:*:*:*:*:*cpe:2.3:o:linux:linux_kernel:7.0:rc3:*:*:*:*:*:*cpe:2.3:o:linux:linux_kernel:7.0:rc4:*:*:*:*:*:*
Affected products
| Product | Versions |
|---|---|
| Linux · Linux | affected efc30877bd4bc85fefe98d80af60fafc86e5775e < 11a87dd5df428a4b79a84d2790cac7f3c73f1f0d ; affected f87271d21dd4ee83857ca11b94e7b4952749bbae < c22a5e659959eb77c2fbb58a5adfaf3c3dab7abf ; affected ab4eedb790cae44313759b50fe47da285e2519d5 < da3000cbe4851458a22be38bb18c0689c39fdd5f ; affected ab4eedb790cae44313759b50fe47da285e2519d5 < 71030f3b3015a412133a805ff47970cdcf30c2b8 ; affected ab4eedb790cae44313759b50fe47da285e2519d5 < 752a6c9596dd25efd6978a73ff21f3b592668f4a ; affected 18ab6b6078fa8191ca30a3065d57bf35d5635761 |
| Linux · Linux | affected 6.14 ; unaffected 0 < 6.14 ; unaffected 6.6.130 ≤ 6.6.* ; unaffected 6.12.78 ≤ 6.12.* ; unaffected 6.18.20 ≤ 6.18.* ; unaffected 6.19.10 ≤ 6.19.* |
Sources
| Source | Licence |
|---|---|
| CVE List (CVEProject cvelistV5) | CVE Program Terms of Use |
| EPSS (FIRST.org) | FIRST — attribution requested |
| ENISA EUVD | ENISA — reproduction authorised, source acknowledged |
| CERT-FR (ANSSI) | Licence Ouverte / Etalab 2.0 |
| NVD (NIST) via fkie-cad/nvd-json-data-feeds | Public domain — this product uses data from the NVD API but is not endorsed or certified by the NVD |