Medium [CVE-2026-63976] clear chan->ident on ECRED reconfiguration success
This medium-severity Red Hat Linux advisory covers CVE-2026-63976 affecting Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 8, Red Hat Enterprise Linux 9.
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Summary
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). A flaw was found in the Linux kernel's Bluetooth L2CAP (Logical Link Control and Adaptation Protocol) implementation.
A remote attacker, acting as a peer, could exploit a vulnerability where the system fails to clear a channel identifier after a successful Enhanced Credit Based Mode (ECRED) reconfiguration.
By replaying a failure response with this stale identifier, the attacker can force the kernel to terminate an active Bluetooth connection, leading to a Denial of Service (DoS).
Affected versions
No affected-version range was extracted from the source record. The vendor advisory is authoritative — check it before change work.
Official advisory · medium-confidence parse· fetched 6 days ago·verify at source
Fixed versions
No fixed release is recorded yet. That does not prove no patch exists — confirm against the vendor advisory.
Official advisory · medium-confidence parse· fetched 6 days ago·verify at source
Mitigation
The source record does not include mitigation steps. That is not a statement that no fix exists — read the vendor advisory below for the authoritative guidance.
Official advisory · medium-confidence parse· fetched 6 days ago·verify at source
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