SB20260814102 - Out-of-bounds read in Linux kernel s390 crypto driver

Description

This security bulletin contains information about 1 vulnerability.

1) Out-of-bounds read (CVE-ID: CVE-2026-68453)

CWE-ID: CWE-125 - Out-of-bounds read

CVSSv4: 6.9 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:H/SC:N/SI:N/SA:N]

The vulnerability allows a local user to cause a denial of service or disclose sensitive information.

The vulnerability exists due to out-of-bounds read in the s390 zcrypt CCA token validation and handling logic when processing crafted CCA key token buffers with user-controlled length fields. A local user can provide a specially crafted key token with inconsistent length values to cause a denial of service or disclose sensitive information.

The issue involves both oversized length fields that exceed the actual buffer size and undersized length fields that can cause a buffer under-run with similar effects.

Remediation

Install update from vendor's website.

References

• https://git.kernel.org/stable/c/36b230835b8a008266aad22168ca52afacc8a58d
• https://git.kernel.org/stable/c/3b2abee2a678607ae27975bc6833785c2002df43
• https://git.kernel.org/stable/c/a57fd7fcdb63e2d5ceac78bbe825ec986062a9da