CVE-2026-68453

Kernel memory disclosure or crash via token length

Published Aug 13, 2026 · Updated Aug 13, 2026

Buffer over-read in the Linux s390/zcrypt subsystem allows local users to expose kernel memory or crash the kernel. The cca_check_sec*token() functions trust user-controlled token lengths without checking the actual buffer or minimum structure size, while cca_gencipherkey() can underflow a returned key size. Low-privileged local access and an attached CCA crypto card are required; crafted lengths can send out-of-bounds memory to the card or crash the kernel.

CVSS severity7.1
High
EPSS probability0.13%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Buffer over-read in the Linux s390/zcrypt subsystem allows local users to expose kernel memory or crash the kernel. The cca_check_sec*token() functions trust user-controlled token lengths without checking the actual buffer or minimum structure size, while cca_gencipherkey() can underflow a returned key size. Low-privileged local access and an attached CCA crypto card are required; crafted lengths can send out-of-bounds memory to the card or crash the kernel.

The record

CVE
CVE-2026-68453
Published
Aug 13, 2026
Updated
Aug 13, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
T1499.004
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Aug 13, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 13, 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=4bc123b18ce6ae6c42c69d0456b5acbd2f7bc8bd <36b230835b8a008266aad22168ca52afacc8a58d
  2. Affected versionversion=4bc123b18ce6ae6c42c69d0456b5acbd2f7bc8bd <3b2abee2a678607ae27975bc6833785c2002df43
  3. Affected versionversion=4bc123b18ce6ae6c42c69d0456b5acbd2f7bc8bd <a57fd7fcdb63e2d5ceac78bbe825ec986062a9da
  4. Affected versionversion=5.4

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=4bc123b18ce6ae6c42c69d0456b5acbd2f7bc8bd <36b230835b8a008266aad22168ca52afacc8a58d; version=4bc123b18ce6ae6c42c69d0456b5acbd2f7bc8bd <3b2abee2a678607ae27975bc6833785c2002df43; version=4bc123b18ce6ae6c42c69d0456b5acbd2f7bc8bd <a57fd7fcdb63e2d5ceac78bbe825ec986062a9da; version=5.4

Published CVSS scores

7.1LinuxCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/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.

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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

T1499.004Application or System Exploitation

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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