Bluetooth: L2CAP: fix chan mode for LE_CONN_REQ + EXT_FLOWCTL pchan
Key facts
- Attack vector
- Adjacent network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- High
- Impact type
- —
- Confidentiality · integrity · availability
- High · High · High
- Fix status
- Partial Red Hat: 5 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: L2CAP: fix chan mode for LE_CONN_REQ + EXT_FLOWCTL pchan l2cap_new_connection() sets default value of channel mode to match the parent channel. l2cap_le_connect_req() left this at the default, and created L2CAP_MODE_EXT_FLOWCTL channels if listening pchan has that mode. This causes FLAG_DEFER_SETUP channels to reply to L2CAP_LE_CONN_REQ with L2CAP_ECRED_CONN_RSP, which is incorrect. It can also result to stack OOB write (of l2cap_alloc_cid determined values) in l2cap_ecred_rsp_defer(), as l2cap_le_connect_req() does not limit maximum number of deferred channels or check for duplicate ident. Fix by setting chan->mode correctly in l2cap_le_connect_req(). Also check channel mode in l2cap_ecred_rsp_defer(), and do WARN_ON_ONCE instead of OOB write to make it less brittle.
Why it matters now
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
Remediation
- Fix · CNA Linux (Linux) Fixed in 5.10.271, 5.15.222, 6.1.189, 6.6.158, 6.12.111, 6.18.53, 7.2.7, 7.3
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 8 | Affected | No fix yet |
| Red Hat Enterprise Linux 9 | Affected | No fix yet |
| Red Hat OpenShift Container Platform 4 | Affected | No fix yet |
| Red Hat OpenShift Container Platform 5 | Affected | No fix yet |
Not affected: 2 products
- Red Hat Enterprise Linux 6
- Red Hat Enterprise Linux 7
Timeline
- 2026-10-02 Threatist record created from CVE-2026-98108
- 2026-10-03 Alias added: GHSA-q3c9-52vx-cgp8
- 2026-10-03 Fix available: Linux/Linux@0e1fc7cab95ad958e55d70a5dfaaea687c9c639f, Linux/[email protected], Linux/[email protected] +5 · CNA
- 2026-10-03 4 new references · CNA
- 2026-10-19 Fix available: Linux/[email protected] · CNA
- 2026-10-27 CVSS score changed · Red Hat
- 2026-10-30 Affected versions changed · Red Hat
References
Other 8
- https://git.kernel.org/stable/c/ad0f44a3f1f688558ed876a0702bc2c82b0df689
- https://git.kernel.org/stable/c/564ae0e05e598aa895b9dbd18cb7d6eb64752869
- https://git.kernel.org/stable/c/aab17938998b29e75c3324763411aef3e300fc67
- https://git.kernel.org/stable/c/0e1fc7cab95ad958e55d70a5dfaaea687c9c639f
- https://git.kernel.org/stable/c/1074bcc57f741223f9fa82ce6afe5c3d783e4d10
- https://git.kernel.org/stable/c/5d5a625cbc854d4c4f68e4b16fcf6e682d9a9ed1
- https://git.kernel.org/stable/c/6cb79e6499228cfdbd4b3301371ce74d01cd2f80
- https://git.kernel.org/stable/c/4ef05db5b08b176a551b4a6287372045998806b0
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Sources
- CVE-2026-98108 · CVE Program
- CVE-2026-98108 · NVD
- FIRST EPSS
- GHSA-q3c9-52vx-cgp8 · GitHub Advisory Database · CC BY 4.0
- CVE-2026-98108 · 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