CVE Catalog

CVE-2026-53241

MediumCVSS 5.5
Published: Updated: Translated: NVD NIST

Exploitation Probability (EPSS)

Low risk
0.13%

3th percentile - higher than 3% of all known CVEs

Summary

In the Linux kernel, the ALSA seq dummy driver has a vulnerability involving a stack overread when processing UMP events. Copying an event into a temporary structure smaller than struct snd_seq_ump_event causes out-of-bounds reads when delivering to subscribers.

Risk Assessment

This vulnerability may lead to leakage of sensitive kernel memory or unexpected system behavior, potentially allowing a local attacker to escalate privileges or destabilize the system.

Recommendation

Immediately update the Linux kernel to a version containing the fix, which uses the __snd_seq_event union for storage and copies the full UMP packet size.

Other vulnerabilities in Linux kernel

See all
Original NVD description (English source)

In the Linux kernel, the following vulnerability has been resolved: ALSA: seq: dummy: fix UMP event stack overread The dummy sequencer port forwards events by copying an incoming struct snd_seq_event into a stack temporary, rewriting source and destination, and dispatching the temporary to subscribers. That legacy event storage is smaller than struct snd_seq_ump_event. When a UMP event reaches the dummy client, the copy leaves the UMP flag set but only provides legacy-sized stack storage. The subscriber delivery path then uses snd_seq_event_packet_size() and copies a UMP-sized packet from that stack object, reading past the end of the temporary. Use the existing union __snd_seq_event storage and copy the packet size reported for the incoming event before rewriting the common routing fields. This preserves the full UMP packet for UMP events while keeping legacy event handling unchanged.

Vulnerability data from NVD (NIST) · CISA KEV · EPSS