CVE-2026-68453

Technical Description

In the Linux kernel, the following vulnerability has been resolved:

s390/zcrypt: Fix buffer over-read in cca_cipher2protkey

Add validation of both the actual key buffer size and token length

fields in all the cca_check_sec*token() functions. Additionally check

in cca_gencipherkey() for possible underflow with returned key size.

The CCA token structures contain user-controlled len fields that

were used in operations without proper validation against both the

actual buffer size and minimum token structure size. An attacker

could set this field larger than the actual buffer size, leading to

reading beyond buffer boundaries. This may result in a kernel crash or

exposure of memory via sending this as part of a request down to the

crypto card. Also an attacker could have used a very small len value

and thus enforce a buffer under-run which may produce similar effects

as a over-read.

So now a key must

- key buf length must be at least sizeof the token struct

- the key len field inside the

Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

References