Use of Uninitialized Variable in Linux kernel - CVE-2026-64479
Published: July 27, 2026
Vulnerability identifier: #VU139457
CSH Severity: Low
CVSS v4: 4.8 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-64479
CWE-ID: CWE-457
Exploitation vector: Local access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a local user to disclose sensitive information.
The vulnerability exists due to an uninitialized heap leak in snd_seq_event_dup() when delivering a legacy event to a UMP client with SNDRV_SEQ_FILTER_NO_CONVERT set. A local user can send a crafted event through /dev/snd/seq to disclose sensitive information.
The issue can leak 4 bytes of stale kernel heap data to user space, and exploitation requires a UMP-enabled build.
Affected software
Linux kernel
How to mitigate CVE-2026-64479
Install security update from vendor's repository.
Linux kernel - update to 7.0 rc3
External References
- https://git.kernel.org/stable/c/435990e25bf1f4af3e6df12a6fbfd1f7ba4a97d4
- https://git.kernel.org/stable/c/651ba82fe2a144bc7356d940bfd235c3810b0549
- https://git.kernel.org/stable/c/6ded42615fa1f4949925afd0a8a9e1ab3bf96202
- https://git.kernel.org/stable/c/a224c84e5d3d35708c082c84ad12d81d90762195
- https://git.kernel.org/stable/c/d7649aa11089a93ea2285c210397aa67e5800766
- https://git.kernel.org/stable/c/ea672a9f6cc38f06fe69dd2c257ef8a3d4db179a
- https://git.kernel.org/stable/c/fb1aa5082847b98f44f9c6272aee9d0dca9244f0