CVE Catalog

CVE-2026-98108

HighCVSS 7.5
Published: Updated: Translated: NVD NIST

Summary

In the Linux kernel, Bluetooth L2CAP's l2cap_le_connect_req() left the channel mode at the default, causing FLAG_DEFER_SETUP channels to reply to L2CAP_LE_CONN_REQ with L2CAP_ECRED_CONN_RSP, which is incorrect. This can lead to an out-of-bounds write in l2cap_ecred_rsp_defer(). The fix sets chan->mode correctly and adds a channel mode check with WARN_ON_ONCE instead of an OOB write.

Risk Assessment

Out-of-bounds write in the Bluetooth stack could lead to system crash or potential remote code execution.

Recommendation

Apply the kernel update containing the L2CAP fix to avoid channel mode issues and out-of-bounds writes.

Other vulnerabilities in Linux kernel

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Original NVD description (English source)

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.

Vulnerability data from NVD (NIST) · CISA KEV · EPSS