Out-of-bounds write in Linux kernel - CVE-2026-93266

Vulnerability details

The vulnerability allows a local user to cause a denial of service.

The vulnerability exists due to a field-spanning write in rsi_attestation_token_init when copying an attestation challenge into the SMCCC register structure. A local user can invoke attestation token initialization with a crafted challenge to cause a denial of service.

Challenge sizes from 32 through 64 bytes are accepted.

Affected software

How to mitigate CVE-2026-93266

External References

• https://git.kernel.org/stable/c/221049874b6a78c7d87bc826581b0695cd338e2b
• https://git.kernel.org/stable/c/d29a8ee271da17b5e32d7a76a9c78d43f66447ca
• https://git.kernel.org/stable/c/e505092cb200d430d5b8d8d3e926d45f29474ba3

Related Security Bulletins

• Out-of-bounds write in Linux kernel include asm