Memory corruption via rounded-up MMIO copies
Published Sep 17, 2026 · Updated Sep 17, 2026
Out-of-bounds access in Linux 6.19 mt76 MMIO helpers allows attackers to read or overwrite memory via unaligned copy lengths. The mt76_mmio_write_copy() and mt76_mmio_read_copy() loops round lengths up to four bytes, reading beyond the source buffer or writing beyond the destination buffer. The trigger requires an mt76 MMIO copy whose length is not divisible by four; an attacker-controlled entry point and further exploitation are not documented.
Summary
What happened
Out-of-bounds access in Linux 6.19 mt76 MMIO helpers allows attackers to read or overwrite memory via unaligned copy lengths. The mt76_mmio_write_copy() and mt76_mmio_read_copy() loops round lengths up to four bytes, reading beyond the source buffer or writing beyond the destination buffer. The trigger requires an mt76 MMIO copy whose length is not divisible by four; an attacker-controlled entry point and further exploitation are not documented.
The record
- CVE
- CVE-2026-90369
- Published
- Sep 17, 2026
- Updated
- Sep 17, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux
- Classifications
- Unavailable
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Sep 17, 2026CVE publishedPublication date reported by the CVE source.
- Sep 17, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
Compare your product and version with the public record. A matching version still requires validation against your environment.
Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=2df00805f7dbaa46b60c682aad0d76270b7ba266 <6689b4a65e88d7b019e687fa9d6943ca070f3e43
- Affected versionversion=2df00805f7dbaa46b60c682aad0d76270b7ba266 <6ed0fba58bb125a8d8de96e391aa86111166efca
- Affected versionversion=6.19
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Activity data is delayed. The latest report is Sep 28, 2026.
Weakness, pattern, technique
No sourced classifications are available.
Public exploit references
No public exploit references are available in this record.
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
See the directory against your own environment.
Your stack
Check the software in your environment
Get started to see how Hinoki identifies affected software and validates exploitability in your environment.
Get started