Vulnerability in Linux
CVE-2026-63976
In the Linux kernel, the following vulnerability has been resolved: Bluetooth: l2cap: clear chan->ident on ECRED reconfiguration success l2cap_ecred_reconf_rsp() returns early on success without clearing chan->ident. Every other L2CAP response handler (l2cap_ecred_conn_rsp, l2cap_le_connect_rsp, l2cap_config_rsp) clears chan->ident after a successful transaction to prevent the channel from matching subsequent responses with the recycled ident value. A remote attacker that completed a reconfiguration as the peer can replay a failure response with the stale ident, causing the kernel to match and destroy the already-established channel via l2cap_chan_del(chan, ECONNRESET). Clear chan->ident for all matching channels on success, and harden the failure path by using l2cap_chan_hold_unless_zero() consistent with other L2CAP handlers (l2cap_le_command_rej, __l2cap_get_chan_by_ident).
EPSS: 0.005 (38.0th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 8.8 (High). Vector: CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.
Affected products
- Linux — versions 15f02b91056253e8cdc592888f431da0731337b8, 5.7, 0
References
Frequently asked questions
- What is CVE-2026-63976?
- CVE-2026-63976 is a high-severity vulnerability in Linux. CVSS score: 8.8/10. Published 2026-07-19.
- How severe is CVE-2026-63976?
- High severity. CVSS v3 base score is 8.8 out of 10.