CVE-2026-98086 ALSA: ump: do not touch legacy_rmidi before it exists
A null pointer dereference in the Linux kernel ALSA UMP driver allows local attackers to cause a system crash via crafted UMP packets.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-98086?
CVE-2026-98086 is a vulnerability in Linux, published on 25 Sep 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
In the Linux kernel, the following vulnerability has been resolved:
ALSA: ump: do not touch legacy_rmidi before it exists
snd_ump_parse_endpoint() sets ump->parsed on every exit, including error, before the caller attaches the legacy rawmidi device. ump_handle_ep_name_msg() then treats parsed as "legacy_rmidi is live" and calls ump_legacy_set_rawmidi_name(), which snprintf()s into ump->legacy_rmidi->name. If a UMP packet arrives in that window (IRQ path from snd_ump_receive), legacy_rmidi is still NULL (KASAN null-ptr-deref in snprintf).
Guard the legacy helpers. parsed only means endpoint info was parsed, not that legacy_rmidi exists.
Which versions are affected by CVE-2026-98086?
How do I fix CVE-2026-98086?
Apply the vendor's patch.
Is CVE-2026-98086 being exploited?
There is no known exploitation of CVE-2026-98086 in the wild and no public exploit code.
Sources
Also known as AZL-104622, BELL-CVE-2026-98086, DEBIAN-CVE-2026-98086, GHSA-54q5-26wc-pgp6, UBUNTU-CVE-2026-98086.