Out-of-bounds read in Linux kernel - CVE-2026-98648

Vulnerability details

The vulnerability allows a local user to cause an out-of-bounds read that may disclose sensitive information or cause a denial of service.

The vulnerability exists due to an out-of-bounds read in the Linux kernel s390/uv function find_secret_in_page when searching a secret-list page using the overall secret count rather than the number of secrets stored on that page. A local user can trigger a search for a secret located on a subsequent page or absent from the list to read beyond the page's secret array, potentially disclosing sensitive information or causing a denial of service.

The issue occurs when the system has more than 85 secrets, exceeding the number of entries held on one page.

Affected software

How to mitigate CVE-2026-98648

External References

• https://git.kernel.org/stable/c/04bb5b2eb9f1d56110f14d3a4e31fa2c65fb026f
• https://git.kernel.org/stable/c/116bba758533a139bbede8d717a1371bd6d890f6
• https://git.kernel.org/stable/c/f47190b08b71e8482072978373ee88cb2dfbdaf4

Related Security Bulletins

• Out-of-bounds read in Linux kernel s390 kernel
• Ubuntu update for linux-oem-7.0
• Ubuntu update for linux, linux-aws, linux-gcp and more