Medium [CVE-2026-68188] Linux kernel Bluetooth RFCOMM: Denial of Service via use-after-free in set_termios
This medium-severity Red Hat Linux advisory covers CVE-2026-68188 affecting Red Hat Enterprise Linux 6, Red Hat Enterprise Linux 7, Red Hat Enterprise Linux 8.
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Summary
In the Linux kernel, the following vulnerability has been resolved: Bluetooth: RFCOMM: Fix session UAF in set_termios rfcomm_tty_set_termios() tests dlc->session without rfcomm_mutex and later passes the pointer to rfcomm_send_rpn(). The latter dereferences both session->initiator and session->sock.
Meanwhile, krfcommd can unlink the DLC and free the session while holding rfcomm_mutex. Have the TTY path use the helper and drop its unlocked session check.
This keeps the session valid through both the frame construction and socket send. A race condition in the `rfcomm_tty_set_termios()` function allows a session to be freed while it is still actively in use.
This use-after-free (UAF) vulnerability can be exploited by a local attacker. Successful exploitation leads to a system crash, resulting in a Denial of Service (DoS).
Red Hat severity: Important — CVSS 4.8 (CVSS:3.1/AV:A/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H). Weakness: CWE-364.
Affected Red Hat products: Red Hat Enterprise Linux 6; Red Hat Enterprise Linux 7; Red Hat Enterprise Linux 8; Red Hat Enterprise Linux 9; Red Hat OpenShift Container Platform 4. Red Hat lists Red Hat Enterprise Linux 10; Red Hat Enterprise Linux for NVIDIA 26 as not affected.
Red Hat does not currently list a fixing RHSA for this CVE.
Affected products named by the advisory: Red Hat package: kernel-rt.
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 1 hour 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 1 hour 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 1 hour ago·verify at source
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