CVE-2026-90220
Received
Received - Intake
BaseFortify
Vulnerability report for CVE-2026-90220, including description, CVSS score, EPSS score, affected products, exploitability, helpful resources, and attack-flow context.
Publication date: 2026-09-17
Last updated on: 2026-09-17
Assigner: kernel.org
Description
Description
In the Linux kernel, the following vulnerability has been resolved:
ALSA: seq: Don't leak the extension cell pointer in the bounce payload
The bounce_error_event() embeds the failed event in the bounce payload
by pointing data.ext.ptr at it. When that event is a queued
variable-length event, its own data.ext.ptr holds the address of its
first extension cell, put there by snd_seq_event_dup(). The payload
goes out verbatim through snd_seq_expand_var_event(), so the address
reaches userspace.
That is the same address commit 705dd6dcbc0e ("ALSA: seq: Clear
variable event pointer on read") removed from the event header. The
read path still clears it there, just above the call that expands the
payload.
Embed a sanitised copy instead, treated exactly as snd_seq_read()
treats the header. A stack copy is enough because delivery is
synchronous and snd_seq_event_dup() copies before returning.
An unprivileged client reaches this by setting SNDRV_SEQ_FILTER_BOUNCE,
queueing a variable-length event to a port that does not exist and
reading the bounce back. Eight bytes on 64-bit, from its own pool.
CVSS Scores
EPSS Scores
| Probability: | |
| Percentile: |
Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| Linux | Linux | 93d260ce43a81df579c98bee92b91316df9c1c57 |
| Linux | Linux | dae23c545eb5a2be3b27a82fd0f611894fb8ab69 |
| Linux | Linux | efc86691e4d8083d9e380ea95042c2cf679f65fd |
| Linux | Linux | efc86691e4d8083d9e380ea95042c2cf679f65fd |
| Linux | Linux | 0527a56cb327021cb73167cfddf0e49efa043500 |
| Linux | Linux | 6.12.97 |
| Linux | Linux | 6.18.40 |
| Linux | Linux | 7.1.5 |
| Linux | Linux | 7.2 |
Helpful Resources
Exploitability
CWE
KEV
| CWE ID | Description |
|---|---|
| CWE-UNKNOWN |
