CyberSecBulletin
CVE-2026-68453NVD status: Received

Linux: Out-of-bounds Read

Published Updated By the CyberSecBulletin desk

CVE-2026-68453 is a high-severity out-of-bounds read vulnerability in Linux, with a CVSS 3.1 base score of 7.1 out of 10. It can be exploited with local access to the system by an attacker with a low-privileged account, without any action from a user. The record lists versions 1adfec7be6f34c1073c9cf15040bc4e3fdc6dc51, d0951ed366710a1a303b7cb2f8eb3d866cd68fc6, 353e442d18084b24fb3ede4e5adfca26b25f0e89 as the first without the flaw, so updating Linux to one of those releases or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.16% chance of exploitation within 30 days, which is low compared with other CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Update Linux to 1adfec7be6f34c1073c9cf15040bc4e3fdc6dc51 or d0951ed366710a1a303b7cb2f8eb3d866cd68fc6 or 353e442d18084b24fb3ede4e5adfca26b25f0e89 or a57fd7fcdb63e2d5ceac78bbe825ec986062a9da, whichever matches your release line, or a later version.

Affected products and versions

VendorProductAffected versionsFixed in
LinuxLinux4bc123b18ce6ae6c42c69d0456b5acbd2f7bc8bd up to, but not including, 1adfec7be6f34c1073c9cf15040bc4e3fdc6dc51; 4bc123b18ce6ae6c42c69d0456b5acbd2f7bc8bd up to, but not including, d0951ed366710a1a303b7cb2f8eb3d866cd68fc6; 4bc123b18ce6ae6c42c69d0456b5acbd2f7bc8bd up to, but not including, 353e442d18084b24fb3ede4e5adfca26b25f0e89; 4bc123b18ce6ae6c42c69d0456b5acbd2f7bc8bd up to, but not including, a57fd7fcdb63e2d5ceac78bbe825ec986062a9da; 4bc123b18ce6ae6c42c69d0456b5acbd2f7bc8bd up to, but not including, 3b2abee2a678607ae27975bc6833785c2002df43; 4bc123b18ce6ae6c42c69d0456b5acbd2f7bc8bd up to, but not including, 36b230835b8a008266aad22168ca52afacc8a58d; 5.41adfec7be6f34c1073c9cf15040bc4e3fdc6dc51, d0951ed366710a1a303b7cb2f8eb3d866cd68fc6, 353e442d18084b24fb3ede4e5adfca26b25f0e89, a57fd7fcdb63e2d5ceac78bbe825ec986062a9da, 3b2abee2a678607ae27975bc6833785c2002df43, 36b230835b8a008266aad22168ca52afacc8a58d

Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Attack vector
LocalThe attacker needs local access or must trick a user into running something.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
Privileges required
LowA basic user account is enough.
User interaction
NoneNo action by a victim is required.
Scope
UnchangedImpact stays within the vulnerable component.
Confidentiality
HighAll data handled by the component can be read.
Integrity
NoneNothing can be modified.
Availability
HighThe component can be taken down completely.

Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H. Scored by CNA.

Official description

In the Linux kernel, the following vulnerability has been resolved: s390/zcrypt: Fix buffer over-read in cca_cipher2protkey Add validation of both the actual key buffer size and token length fields in all the cca_check_sec*token() functions. Additionally check in cca_gencipherkey() for possible underflow with returned key size. The CCA token structures contain user-controlled len fields that were used in operations without proper validation against both the actual buffer size and minimum token structure size. An attacker could set this field larger than the actual buffer size, leading to reading beyond buffer boundaries. This may result in a kernel crash or exposure of memory via sending this as part of a request down to the crypto card. Also an attacker could have used a very small len value and thus enforce a buffer under-run which may produce similar effects as a over-read. So now a key must - key buf length must be at least sizeof the token struct - the key len field inside the token must fit into the range of sizeof key token struct ... key buf length

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Out-of-bounds Read

The product reads data past the end, or before the beginning, of the intended buffer.

How developers prevent this class of flaw

  • Use a language that provides appropriate memory abstractions.

More Out-of-bounds Read vulnerabilities (CWE-125)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: partial).
  3. Record last changed materially (score, affected products, status or references).

References

Recent Out-of-bounds Read vulnerabilities

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