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

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.

Published: 2026-05-01 Last update: 2026-05-07 Assigner: 416baaa9-dc9f-4396-8d5f-8c081fb06d67 Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
NVD Status：Analyzed，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2026-31746 is rated Low Risk (23.4/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.02%). Monitor for updates and reassess as exploit intelligence or EPSS changes.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2026-31746

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-05-02 — 0.02% —

Full EPSS history (1 record total)

Common vulnerability scoring system (CVSS) metrics for CVE-2026-31746

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
5.5 3.1 MEDIUM
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H Click to expand
Attack vector (AV:L)
They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 1.8 3.6 [email protected]

Weakness enumeration for CVE-2026-31746

GitHub Security Advisory for CVE-2026-31746

GHSA-rvh3-5jfr-6p58 · Severity: medium — In the Linux kernel, the following vulnerability has been resolved: s390/zcrypt: Fix memory leak...

OS Trackers for CVE-2026-31746

vendor priority summary link
debian unimportant CVE-2026-31746 unimportant priority: Debian including 1 source packages (linux), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2026-31746
redhat — — https://access.redhat.com/security/cve/CVE-2026-31746
suse low CVE-2026-31746 severity low: SUSE including 21 source package names (cluster-md-kmp-default, dlm-kmp-default, …), 196 product×package rows across 38 product lines (SUSE Linux Enterprise High Availability Extension 15 SP7, SUSE Linux Enterprise High Performance Computing 15 SP4-LTSS, … (38 product lines)): Known Not Affected 196. https://www.suse.com/security/cve/CVE-2026-31746/
ubuntu medium CVE-2026-31746 medium priority: Ubuntu including 161 source packages (linux, linux-allwinner-5.19, …), 1449 status rows across 9 suites (bionic, focal, jammy, noble, questing, resolute, trusty, upstream, xenial): DNE 1047, ignored 169, not-affected 125, released 84, needed 19, needs-triage 5. https://ubuntu.com/security/CVE-2026-31746

Affected software / configurations for CVE-2026-31746

Vendor Product Version Raw CPE
linux linux_kernel >= 6.16, < 6.18.22 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
linux linux_kernel >= 6.19, < 6.19.12 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
linux linux_kernel 7.0 cpe:2.3:o:linux:linux_kernel:7.0:rc1:*:*:*:*:*:*
linux linux_kernel 7.0 cpe:2.3:o:linux:linux_kernel:7.0:rc2:*:*:*:*:*:*
linux linux_kernel 7.0 cpe:2.3:o:linux:linux_kernel:7.0:rc3:*:*:*:*:*:*
linux linux_kernel 7.0 cpe:2.3:o:linux:linux_kernel:7.0:rc4:*:*:*:*:*:*
linux linux_kernel 7.0 cpe:2.3:o:linux:linux_kernel:7.0:rc5:*:*:*:*:*:*
linux linux_kernel 7.0 cpe:2.3:o:linux:linux_kernel:7.0:rc6:*:*:*:*:*:*

References for CVE-2026-31746

cvelogic Threat Intelligence