CVE-2026-80708 s390/zcrypt: Fix missing mem scrub at clear key import in cca_clr2cipherkey()
An attacker with local access could potentially read sensitive cryptographic key material from memory due to missing buffer scrubbing in the s390 zcrypt driver.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-80708?
CVE-2026-80708 is a vulnerability in Linux, published on 28 Aug 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
In the Linux kernel, the following vulnerability has been resolved:
s390/zcrypt: Fix missing mem scrub at clear key import in cca_clr2cipherkey()
The helper function _ip_cprb_helper() uses internal buffer memory for building and processing CPRBs. After use this buffer was never scrubbed which could lead to leaving for example clear key material in memory which could be exposed via tricky reuse of this same memory.
Extend the _ip_cprb_helper() function with another parameter 'scrub' used to steer scrubbing of this buffer. So now the caller has the opportunity to decide if scrubbing is needed or not.
Extend the clear key to secure key token import process in function cca_clr2cipherkey() to tell the helper function from above to scrub the cprb buffer when the clear key value is part of the request data.
Add explicit scrubbing on return from function cca_clr2cipherkey() for the random EXOR buffer and the cprb buffer.
Overall this cleans the internal used buffer in case of clear key import to prevent sensitive data to get exposed.
Which versions are affected by CVE-2026-80708?
How do I fix CVE-2026-80708?
Apply the vendor's patch.
Is CVE-2026-80708 being exploited?
There is no known exploitation of CVE-2026-80708 in the wild and no public exploit code.
Sources
Also known as AZL-98060, BELL-CVE-2026-80708, DEBIAN-CVE-2026-80708, GHSA-4hj9-w4jr-3vw2, UBUNTU-CVE-2026-80708.