CVE-2026-90207
High CVSS 7.8Published 2026-09-17 ยท last changed 2026-09-18
The fix
We hold no Microsoft remediation data for CVE-2026-90207, which normally means it is not a Windows CVE. For non-Microsoft software the fix is the vendor's own updated release, and the affected versions are listed below.
What it is
In the Linux kernel, the following vulnerability has been resolved: ALSA: seq: midi: Serialize input teardown with event_input snd_midi_input_event() must not be running while a rawmidi substream is closing, since this can lead to the trigger state becoming out-of-step through this sequence in snd_rawmidi_input_trigger(): snd_rawmidi_input_trigger(up=0) snd_midi_input_event() -> snd_rawmidi_kernel_read() -> snd_rawmidi_input_trigger(up=1) -> cancel_work_sync() which ends with the underlying device being active unexpectedly. When this is called from close_substream(), further input can re-trigger the input event leaving it running after rawmidi_release_priv() has set rfile->rmidi to NULL which leads to: Unable to handle kernel NULL pointer dereference at virtual address 00000000000000b0 Call trace: snd_midi_input_event+0x3c/0x134 [snd_seq_midi] (P) snd_rawmidi_input_event_work+0x1c/0x2c process_one_work+0x150/0x3a4 worker_thread+0x190/0x318 Apply a similar approach to commit ef7607ab1c8ad ("ALSA: seq: midi: Serialize output teardown with event_input") which fixed the same issue in the output direction, but updated to use RCU following Takashi Iwai's proposed follow-on patch [1]. With this change in place, midisynth_unsubscribe() clears the input file so snd_midi_input_event() will not re-trigger the stream and will be quiesced by the cancel_work_sync() in snd_rawmidi_input_trigger(). [1] https://lore.kernel.org/linux-sound/20260813144224.753399-1-tiwai@suse.de/
Sources
CVSS vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H