CVE-2026-74466

Speculative memory reads via unchecked domain index

Published Aug 15, 2026 · Updated Aug 15, 2026

Out-of-bounds read in the Linux kernel allows local users to perform speculative memory reads through a crafted s390 zcrypt ioctl domain. While preparing a CCA or EP11 request block, zcrypt_api.c bounds-checks the user-controlled domain but indexes an array without array_index_nospec(), permitting transient access beyond the validated range. Reachability requires a custom device node and administrative load on an s390 system using the affected cryptographic-device path; public sources do not demonstrate extraction of the transiently read data.

CVSS severity5.5
Medium
EPSS probability0.17%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Out-of-bounds read in the Linux kernel allows local users to perform speculative memory reads through a crafted s390 zcrypt ioctl domain. While preparing a CCA or EP11 request block, zcrypt_api.c bounds-checks the user-controlled domain but indexes an array without array_index_nospec(), permitting transient access beyond the validated range. Reachability requires a custom device node and administrative load on an s390 system using the affected cryptographic-device path; public sources do not demonstrate extraction of the transiently read data.

The record

CVE
CVE-2026-74466
Published
Aug 15, 2026
Updated
Aug 15, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-125
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Aug 15, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 15, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=5.18
  2. Affected versionversion=cfd68b33094e1a92249850ff3c3c92ae9112a541 <82b62eda68abfb7a33ac40f24b8c4128c2891148
  3. Affected versionversion=cfd68b33094e1a92249850ff3c3c92ae9112a541 <e935cd525af4c6ed2e2c6404aa27ca19c7f39ddb

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=5.18; version=cfd68b33094e1a92249850ff3c3c92ae9112a541 <82b62eda68abfb7a33ac40f24b8c4128c2891148; version=cfd68b33094e1a92249850ff3c3c92ae9112a541 <e935cd525af4c6ed2e2c6404aa27ca19c7f39ddb

Published CVSS scores

5.5Red HatCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-125Out-of-bounds Read

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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